MEMS device for interferometric spectroscopy

ABSTRACT

The present application relates to a system for performing time-resolved interferometric spectroscopy of incoming light. In some embodiments, the system includes one or more optical elements, a photo-detector, a capacitance detector, and one or more processors. Upon application of a varying input signal to the one or more optical elements, a change to an optical characteristic is caused resulting in a changing interference pattern produced by the incoming light incident on the one or more optical elements. During the application of the varying input signal, the photo-detector may detect an intensity of light output from the one or more optical elements and the capacitance detector may detect a capacitance of the one or more optical elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. application Ser. No.62/995,197, filed Jan. 17, 2020, entitled “Time resolved interferometricspectrometer,” the disclosure of which is hereby incorporated byreference in its entirety.

BACKGROUND 1. Field

The present disclosure relates generally to interferometricspectroscopy, and in particular, micro-electromechanical system (MEMS)devices capable of performing time-dependent interferometricspectroscopy.

2. Description of the Related Art

Spectroscopy is a technique whereby an intensity of incident light as afunction of wavelength is measured. The measured spectrum of light canbe used for a variety of functions, such as resolving a materialcomposition of matter with which the incident light interacts.Interferometric devices, also referred to as “interferometers,” aredevices used to analyze the incident light. Interferometers harness thewave-like propriety of light to determine the wavelength(s) of theincident light. Constructive and destructive interference of light causeparticular intensity patterns to be produced, and, using the intensitypattern, a wavelength of the incident light can be resolved.

One type of interferometer that is used is a Fabry-Perot Interferometer.The Fabry-Perot Interferometer includes two plates that are partiallyreflective and partially transmissive (e.g., two glass plates having areflective coating on an inner surface), which are spaced apart from oneanother by a small air gap. Interference is created when the incidentlight passing through the plates interacts with light reflecting off theinner surfaces of the plates. The resulting intensity pattern shows aprominent peak around one particular wavelength with a possible secondpeak, third peak, or more peaks, corresponding to second, third, andhigher order interference, also possibly being visible.

Existing interferometers are large and unable to be packaged smallenough to be used as micro-electro mechanical systems (MEMS). Forexample, existing interferometers employ plates of the order of 0.5inches. While the gap between the plates is of the same order as MEMSdevices, the actual size of the interferometer is much larger than thoseof MEMS devices. Furthermore, existing interferometric devices are slowto operate and resolve only a finite region of wavelengths. These and/orother drawbacks exist.

SUMMARY

The following is a non-exhaustive listing of some aspects of the presenttechniques. These and other aspects are described in the followingdisclosure.

In some embodiments, a system for operating on incoming light isprovided. The system may include at least one of one or more opticalelements, a photo-detector, a capacitance detector, a current detector,or one or more processors. The one or more optical elements, uponapplication of a varying input signal, may cause a change to an opticalcharacteristic of the one or more optical elements resulting in achanging interference pattern produced by incoming light incident on theone or more optical elements. The photo-detector may be configured todetect an intensity of light output from the one or more opticalelements during application of the varying input signal. The capacitancedetector may be configured to detect a capacitance associated with theoptical characteristic of the one or more optical elements during theapplication of the varying input signal. The current detector may beconfigured to detect a current drawn by the one or more optical elementsduring the application of the varying input signal. The one or moreprocessors may be configured to obtain, from the capacitance detector, aplurality of capacitance values representing the capacitance of the oneor more optical elements. Alternatively or additionally, the currentdetector may be configured to obtain a plurality of current valuesrepresenting the current drawn by, of the one or more optical elements.The one or more processors may be further configured to obtain, from thephoto-detector, a plurality of signal values representing the intensityof light output from the one or more optical elements; and generate aplurality of transformation values respectively based on the pluralityof capacitance and/or current values.

In some embodiments, a method for operating on incoming light isprovided. The method, which may be implemented by one or more processorsexecuting computer program instructions, includes: obtaining, from acapacitance detector configured to detect a capacitance associated withan optical characteristic of one or more optical elements duringapplication of a varying input signal, a plurality of capacitance valuesrepresenting the capacitance of the one or more optical elements,wherein upon application of the varying input signal, the one or moreoptical elements cause a change to the optical characteristic therebyresulting in a changing interference pattern produced by incoming lightincident on the one or more optical elements; obtaining, from aphoto-detector configured to detect an intensity of light output fromthe one or more optical elements during application of the varying inputsignal, a plurality of signal values representing the intensity of thelight output from the one or more optical elements; and generating aplurality of transformation values respectively based on the pluralityof capacitance values, wherein the plurality of transformation valuesand the plurality of signal values are used to determine a spectrum ofthe incoming light. In some embodiments, the method further includesdetermining a current drawn by the one or optical elements, wherein thecapacitance is determined based on the current.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects and other aspects of the present techniqueswill be better understood when the present application is read in viewof the following figures in which like numbers indicate similar oridentical elements:

FIG. 1A illustrates a block diagram example of a system for performinginterferometric spectroscopy, in accordance with various embodiments;

FIG. 1B illustrates an example of the capacitance detector circuitry ofthe system of FIG. 1A, in accordance with various embodiments;

FIG. 1C illustrates an example of the current detector circuitry of thesystem of FIG. 1A, in accordance with various embodiments;

FIG. 2 illustrates an example of a data structure stored in memoryincluding measured intensities and capacitances, in accordance withvarious embodiments;

FIG. 3 illustrates an example of an optical element from side-view, inaccordance with various embodiments;

FIG. 4 illustrates an example of a plot depicting a spectraltransmission characteristics for an example optical element, inaccordance with various embodiments;

FIG. 5 illustrates another example of an optical element from aside-view, in accordance with various embodiments;

FIGS. 6A and 6B illustrate another example of an optical element fromside-view and a top-view, respectively, in accordance with variousembodiments;

FIGS. 7A and 7B illustrate an example of systems for performinginterferometric spectroscopy, in accordance with various embodiments;

FIGS. 8A-8H illustrate an example process for fabricating an opticalelement for performing interferometric spectroscopy, in accordance withvarious embodiments;

FIGS. 9A and 9B illustrate additional example optical elements forperforming interferometric spectroscopy, in accordance with variousembodiments;

FIGS. 10A and 10B illustrate examples of alternate techniques formeasuring a gap of an interferometer, in accordance with variousembodiments; and

FIG. 11 illustrates an example flowchart of a process for obtaining datafor resolving a spectrum of incident light, in accordance with variousembodiments.

While the present techniques are susceptible to various modificationsand alternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will herein be described in detail. Thedrawings may not be to scale. It should be understood, however, that thedrawings and detailed description thereto are not intended to limit thepresent techniques to the particular form disclosed, but to thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the presenttechniques as defined by the appended claims.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

To mitigate the problems described herein, the inventor had to bothinvent solutions and, in some cases just as importantly, recognizeproblems overlooked (or not foreseen) by others in the field ofspectroscopy and MEMS devices. Indeed, the inventor wishes to emphasizethe difficulty of recognizing those problems. Further, because multipleproblems are addressed, it should be understood that some embodimentsare problem-specific, and not all embodiments address every problem withtraditional systems described herein or provide every benefit describedherein. That said, improvements that solve one or more permutations ofthese problems and/or other problem(s) are described below.

The present application relates to systems and methods for obtainingdata that can be used to obtain a spectrum of incoming electromagneticradiation. The incoming electromagnetic (EM) radiation includeswavelengths in the visible range (e.g., 400-700 nm), infrared range(e.g., 700 nm-1 mm), ultraviolet range (e.g., 10 nm-400 nm), or otherwavelength ranges. The present application describes miniaturizedspectrometers and various applications for such miniaturizedspectrometers. In some cases, as few as one miniaturized spectrometercan be used to resolve an entire spectrum of EM radiation, while othercases include more than one miniaturized spectrometer (e.g., 10 or less,5 or less). Different wavelengths of EM radiation interact withdifferent materials (e.g., partially or fully absorbed). Depending on anobject's material composition, different wavelengths of EM radiationwill be absorbed or reflected. In some embodiments, the spectrum of theEM radiation that remains, either transmitted or reflected, afterinteracting with the object can be analyzed to determine the object'smaterial composition.

In some embodiments, the spectrometers described herein are of the orderof a few millimeters in length, width, and height, allowing forintegration into mobile devices (e.g., smartphones, tablets,smartwatches, etc.). As a result, the number of possible applicationsfor the spectrometers increases exponentially. Some examples of theseapplications include contactless or near-contactless determinations ofbiological information (e.g., a blood-oxygen level, cholesterol levels,glucose levels, blood-alcohol levels, etc.), determining a spectrum oflight captured by an image using a camera, determining an object'smaterial composition, and more.

Previous techniques required multiple spectrometers to analyze aspectrum of incident EM radiation due to the small wavelength range thatprevious spectrometers span. Therefore, in order to resolve an entirespectrum of the incoming EM radiation, multiple spectrometers, eachtuned for a different, small, range of wavelengths, are needed.Moreover, multiple measurement cycles are needed to capture differentranges of wavelengths of the incident EM radiation for eachspectrometer. Additionally, these spectrometers are much larger thanwhat can be integrated into mobile devices, particularly as mobiledevices decrease in size and increase in capability. For example,conventional interferometers used to perform spectroscopy use gratingsand linear detector arrays and can have a footprint of 0.5-1.0 inches,making integration into modern mobile devices unfeasible. Additionally,conventional interferometers resolve interference patterns in a spatialdomain, such as with the Newton rings interference pattern produced by aFabry-Perot interferometer, or using gratings to spread the spectruminto a spatial pattern.

The systems, devices, and techniques described herein overcome theaforementioned problems associated with conventional spectroscopydevices. In particular, the present application describesinterferometers small enough to be integrated into modern mobile devices(e.g., of the order of a few millimeters), while still being capable ofobtaining a large portion of the spectrum of incoming EM radiation.Further still, the present application describes techniques formeasuring the capacitance between conductive elements of aninterferometer making gap determination unambiguous.

FIG. 1A illustrates an example of a system 10 for performinginterferometric spectroscopy, in accordance with various embodiments.System 10 includes one or more optical elements 100, a photo-detector110, a capacitance detector 120, a current detector 125, one or moreprocessors 130, a MEMS driving circuit 140, memory 150, or othercomponents. In some embodiments, system 10 may include additionalphoto-detectors and/or capacitance detectors, or other components.Incoming EM radiation 102 may incident optical element 100. EMradiation, as described herein, may be referred to interchangeably as“light,” unless specified otherwise. In some embodiments, EM radiation102 reflects off of an object prior to being incident on optical element100. In some embodiments, EM radiation 102 may pass through a portion ofan object (e.g., is partially absorbed) prior to being incident onoptical element 100. In some embodiments, EM radiation 102 is outputdirectly from a source (e.g., an LED, the Sun, etc.). The object may becomposed of one or more materials. For example, the object may be aninanimate object (e.g., a gem, a food, etc.), a portion of a livingcreature (e.g., a finger of a human for determining blood oxygen levels,a portion of skin with which an abnormality to be examined is located,etc.), gases (e.g., the Earth's atmosphere, a portion of the sky, etc.),or other objects.

Optical elements 100, which is described in greater detail below,represents one or more components used to determine a spectrum of EMradiation 102. In some embodiments, optical element 100 is aninterferometer. For example, optical element 100 may be a Fabray-Perotinterferometer. A Fabray-Perot interferometer, which may also bereferred to herein interchangeably as a “Fabray-Perot etalon,” or an“etalon,” is an optical device that harnesses the wave/particle-likeproperties of light to produce an interference pattern. In general,Fabray-Perot interferometers include two parallel plates separated by asmall gap. The plates generally are transmissive and an inner surface ofeach plate is reflective or is coated with a reflective material. Lightthat incidents the plates will both pass through the plates and reflectoff the inner (reflective) surfaces, which subsequently interfere—bothconstructively and destructively—with one another. The resultingintensity pattern is commonly that of an optical band-pass filter. Thetransmission coefficient of a Fabry-Perot interferometer is a periodicfunction of the phase shift induced by the air gap, as seen by Equation1:

$\begin{matrix}{\delta = {\frac{2\pi}{\lambda}{nd}\cos{\theta.}}} & {{Equation}1}\end{matrix}$

In Equation 1, d represents the distance between the inner surfaces ofthe two parallel plates (also referred to as the “gap”), n is the indexof refraction of the gap material (usually air), θ represents the angleof incidence of the incoming EM radiation, and λ represents thewavelength of the EM radiation. The transmission coefficient is maximumwhen δ=mπ where m is the order of interference, and minimum half waybetween these values. These peaks in transmission are called fringes(interference pattern).

In some embodiments, EM radiation 104 (e.g., light) is output fromoptical element 100 and is received by photo-detector 110.Photo-detector 110, which may also be referred to as a “photosensor,” isa device configured to detect EM radiation incident thereon, such as EMradiation 104. The transmitted EM radiation (e.g., EM radiation 104)incident on photo-detector 110 is comprised of photons, hence the name“photo-detector.” An example of photo-detector 110 includes acharge-coupled device (CCD), however different or alternative types ofphoto-detectors can be used. In some embodiments, photo-detector 110 isconfigured to detect incident photons and convert the photons into anelectrical signal (e.g., an electrical current).

EM radiation 104 transmitted from optical element 100 and detected byphoto-detector 110 produces an interference pattern. For example, ifoptical element 100 is a Fabray-Perot interferometer, or a similar typeof interferometer, the interference pattern is depicted as a band-passfilter. This characteristic interference pattern may be formed by theincoming EM radiation constructively and destructively interfering withitself, as portions of incoming EM radiation 102 pass through theparallel plates while others portions of incoming EM radiation 102 arereflected by the parallel plates. For example, as seen in FIG. 4 below,the interference is in wave-number space or wavelength space. Regions oflow transmission in the interference pattern correspond to destructiveinterference, whereas regions of high transmission in the interferencepattern correspond to constructive interference.

In some embodiments, capacitance detector 120 is configured to detect aninstantaneous mutual capacitance of optical element 100. For example, ifoptical element 100 is a Fabry-Perot etalon, then capacitance detector120 is configured to detect an instantaneous mutual capacitance betweenconductive layers of the parallel plates of the Fabry-Perot etalon. Thecapacitance between the parallel plates of a Fabry-Perot etalon can bemeasured with various techniques. For example, a time dependent voltagecan be applied between the parallel plates and a time evolution of thecurrent drawn by the parallel plates can be monitored. In someembodiments, MEMS driving circuit 140, which is described in greaterdetail below, is configured to drive the modulation of the parallelplates, whereas capacitance detector 120 is configured to detect aninstantaneous capacitance between the parallel plates of the Fabry-Perotinterferometer. The capacitance of the parallel plates is a function ofa distance between the plates. The larger the distance, or “gap,”between the two parallel plates, the weaker the mutual capacitance willbe. In some embodiments, capacitance detector 120 is configured tomeasure the capacitance of optical elements 100 responsive to receivinga trigger. The trigger can be an electrical signal that, when receivedby capacitance detector 120, causes capacitance detector 120 to measurethe capacitance of optical elements 100. One example of a capacitancedetector is a capacitance meter, which functions by measuring a voltageacross a parallel plate capacitor based on an input (known) current usedto charge the capacitor. Additional details regarding capacitancedetector 120 is described below with respect to FIG. 1B.

In some embodiments, current detector 125 is configured to detect acurrent drawn by optical element 100. The current of optical element 100can be measured with various techniques. For example, a time dependentcurrent can be applied to optical element 100 and a time evolution ofthe current drawn by the parallel plates can be monitored. The magnitudeof the current drawn by optical element 100, and, in particular, theparallel plates of optical element 100 (e.g., for optical element 100being a Fabry-Perot interferometer), is a function of a distance betweenthe plates. The larger the distance, or “gap,” between the two parallelplates, the smaller the drawn current will be. In some embodiments,current detector 125 is configured to measure the current drawn byoptical elements 100 responsive to receiving a trigger. The trigger canbe an electrical signal that, when received by current detector 125,causes current detector 125 to measure the current drawn by opticalelements 100. Additional details regarding current detector 125 isdescribed below with respect to FIG. 1C.

In some embodiments, MEMS driving circuit 140 is configured to drive themodulation of the parallel plates of optical element 100. For example,MEMS driving circuit 140 may be configured to cause the parallel platesof optical element 100 to modulate at a first frequency. The firstfrequency may be 500 Hz or more, 1,000 Hz or more, 5,000 Hz or more,10,000 Hz or more, or other frequencies. A user can input the desiredfrequency via processors 130, or the desired frequency can be retrievedby processors 130 from memory 150, and then may be provided to MEMSdriving circuit 140 to effectuate the modulation of the parallel platesof optical element 100. For example, MEMS driving circuit 140 maygenerate an output a driving signal, which may be a varying input signal(e.g., a time-dependent signal), whose application to the parallelplates of optical element 100 causes the parallel plates to modulate.The modulate can refer to one of the plates oscillating or both platesoscillating.

In some embodiments, capacitance detector 120 is configured to measurethe instantaneous capacitance at a second frequency. In someembodiments, current detector 125 is configured to measure the currentdrawn at the second frequency. The second frequency may be the same ordifferent than the first frequency. In some cases, the second frequencyis selected based on the first frequency, or vice versa. As an example,the second frequency may be 1,000 Hz or more, 2,000 Hz or more, 10,000Hz or more, 20,000 Hz or more, or other frequencies. In someembodiments, capacitance detector 120 and/or current detector 125provides a voltage to optical element 100 to facilitate the capacitanceand/or current measurement. The voltage provided by capacitance detector120 and/or current detector 125 acts as a superimposed voltage withrespect to the voltage applied to optical element 100 by MEMS drivingcircuit 140 to cause the parallel plates to modulate. In someembodiments, if the parallel plates are not conductive and opticalelement 100 includes additional conductive elements, capacitancedetector 120 and/or current detector 125 provides the voltage to theadditional conductive elements to cause the parallel plates of opticalelement 100 to modulate. For example, a conductive ring around theoptical opening can be used to modulate the parallel plates of opticalelement 100, or can be used to measure the capacitance of opticalelement 100, which serves as a proxy for the size of the air gap betweenthe parallel plates.

Processors 130 may be configured to generate a trigger signal causing(i) photo-detector 110 and (ii) capacitance detector 120 and/or currentdetector 125 to simultaneously measure an intensity of EM radiation 104and measure a capacitance and/or current of optical elements 100,respectively. In some embodiments, the trigger signal is a square wave,however other waveforms may be used (e.g., sinusoidal wave, sawtoothwave, etc.). The trigger signal can take the form of a series of shortpulses (e.g., square pulses). Photo-detector 110, capacitance detector120, and current detector 125 may each be configured to take ameasurement—an intensity measurement, a capacitance measurement, acurrent measurement—at each pulse. In some embodiments, processors 130generate the trigger signal such that the trigger signal is produced andoutput to both photo-detector 110 and capacitance detector 120 at apredetermined frequency. In some embodiments, processors 130 generatethe trigger signal such that the trigger signal is produced and outputto both photo-detector 110 and current detector 125 at the predeterminedfrequency. In some embodiments, processors 130 generate the triggersignal such that the trigger signal is produced and output tophoto-detector 110, capacitance detector 120, and current detector 125,at the predetermined frequency. The frequency with which photo-detector110, capacitance detector 120, and/or current detector 125 measure isthe same or substantially similar. For example, the trigger signal maybe generated such that photo-detector 110 and capacitance detector 120simultaneously measure the intensity of EM radiation 104 and thecapacitance of optical elements 100 at a frequency of 100 Hz or more,500 Hz or more, 750 Hz or more, 1,000 Hz or more, 10,000 Hz or more, andthe like. Similar operations can occur if current detector 125 is usedinstead of, or in addition to, capacitance detector 120. Thehigh-frequency of the trigger signal corresponds to a large number ofmeasurements being captured by both photo-detector 110, capacitancedetector 120, and/or current detector 125. In some embodiments,processors 130 are programed to cause photo-detector 110 and capacitancedetector 120, photo-detector 110 and current detector 125, orphoto-detector 110, capacitance detector 120, and current detector 125to trigger a single sampling event for every instance of the periodictrigger signal (e.g., a square wave) going through a rising edge and afalling edge. That way for every full period, two measurement events aretriggered. As an example, if capacitance detector 120 is configured tosample the capacitance at a frequency of 10,000 Hz, then measurementevents are triggered at a frequency of 20,000 Hz. As described herein, atrigger signal being transmitted to two or more components (e.g.,photo-detector 110, capacitance detector 120, current detector 125) ofsystem 10 “simultaneously” corresponds to the digital signal beingreceived by each of the components within a threshold amount of time Δtof one another, where Δt is approximately 0 seconds (e.g., less than10⁻³ s, less than 10⁻⁶ s, less than 10⁻⁹ s, etc.). In some embodiments,processors 130 may generate and output the trigger signal to account forany lag in signal transmission times such that the trigger signal willbe received by photo-detector 110, capacitance detector 120, and/orcurrent detector 125 at substantially the same time (e.g., within timeΔt of one another). Given that in a preferred embodiment these are MEMSstructures, with the distance of conductors being less than acentimeter, and the speed of light being known, the trigger signal willreach the various detectors at times that are not typically able to bedifferentiated.

In some embodiments, processors 130 are further configured to generate adriving signal that is output to MEMS driving circuit 140. The drivingsignal indicates a value of an electrical signal that is to be generatedby MEMS driving circuit 140 and applied to optical elements 100 to causeone or more components of optical elements 100 to vary, thereby inducinga desired interference pattern. In some embodiments, the driving signalcauses the components of optical element 100 to vary at a resonancefrequency of optical element 100. In some embodiments, MEMS drivingcircuit 140 is be configured to generate a varying electrical signalthat is applied to optical elements 100. For example, the varyingelectrical signal may be a time-dependent voltage, a time-dependentcurrent, or a time-dependent charge. During a first phase of the varyingelectrical signal, a first voltage, current, or charge, may be appliedby MEMS driving circuit 140 to optical elements 100, whereas during asecond phase of the varying electrical signal, a second voltage,current, or charge may be applied. For example, the varying electricalsignal may be a sinusoidal signal, a sawtooth signal, a square-wavesignal, or may be of another functional form.

In some embodiments, the varying electrical signal generated by MEMSdriving circuit 140 and applied to optical elements 100 is configured tocause a capacitance of an optical characteristic of optical elements 100to vary. For example, if optical elements 100 include a parallel plateinterferometer having a gap of air between the two parallel plates, thenapplication of the varying electrical signal causes the gap to vary. Insome embodiments, the gap between the parallel plates represents theoptical characteristic of optical element 100. By varying the gap, thedistance between the parallel plates changes and thus the capacitance(or current drawn) will also change. As another example, if opticalelement 100 includes a parallel plate interferometer having a gapbetween the two parallel plates filled with a birefringent dielectricmaterial, such as a liquid crystal, then application of the varyingelectrical signal causes the dielectric constant of the dielectricmaterial to vary. By varying the dielectric constant, the capacitanceacross the parallel plates (or current drawn) will also vary. As stillyet another example, if optical element 100 includes a parallel plateinterferometer having a gap between the two parallel plates, where theparallel plates are non-conductive and conductive elements arepositioned on an external portion of the parallel plates, thenapplication of the varying electrical signal to the conductive elementscan cause the conductive elements to generate an electromagnetic forcethat pushes or pulls the parallel plates towards or away from oneanother, thereby varying the gap between the parallel plates.

In some embodiments, system 10 includes memory 150 that stores thedetected intensities of the light incident on photo-detector 110, andmay provide the captured intensities to processors 130 after ameasurement cycle (e.g., after processors 130 stop sending the triggersignals). In some embodiments, photo-detector 110 may send each detectedintensity to processors 130 in response to photo-detector 110 capturingthe intensity. In this case, processors 130 stores each detectedintensity measurement in memory 150. In some embodiments, each detectedintensity may be stored in a data structure including a timestamp orother metadata indicating a time, order, or other indicator, of whenthat intensity measurement occurred. In some cases, each trigger signaloutput from processors 130 may include an identifier indicating a time,order, or other indicator, with which it was produced, and the sameidentifier may be stored in association with the measured intensitydetected by photo-detector 110 in response to receiving that digitalsignal.

Memory 150 may also store the instantaneous capacitances detected bycapacitance detector 120. Memory 150 may also store the instantaneouscurrents detected by current detector 125. In some embodiments, memory150 is provided with the detected capacitances and/or detected currentsafter the measurement cycle. Alternatively, the detected capacitancesand/or detected currents may be provided to processors 130 after eachmeasurement by capacitance detector 120, current detector 125, or both,and processors 130 can store the detected capacitances and/or detectedcurrents in memory 150 thereafter. Similarly to the detected intensitiesdescribed above, in some embodiments, the each detected capacitancesand/or detected currents may be stored in a data structure, which may bethe same or different from the data structure used to store the detectedintensities, including a timestamp or other metadata indicating a time,order, or other indicator, of when that intensity was captured. In somecases, each digital signal output from processors 130 may include anidentifier indicating a time, order, or other indicator, with which itwas produced, and the same identifier may be stored in association withthe instantaneous and/or detected currents capacitances measured bycapacitance detector 120 in response to receiving that digital signal.

FIG. 1B illustrates an example of capacitance detector 120 of the systemof FIG. 1A, in accordance with various embodiments. For simplicity, andto avoid obfuscating components, current detector 125 is notillustrated. Similar to FIG. 1A, FIG. 1B depicts a system 20 includingoptical elements 100, photo-detector 110, capacitance detector 120,processors 130, and MEMS driving circuit 140. In FIG. 1B, opticalelements 100 may include components, such as a first plate 102 a and asecond plate 102 b. First plate 102 a and second plate 102 b mayrepresent parallel plates, such as with a Fabry-Perot interferometer.For example, as mentioned above, incoming EM radiation 102 may incidentoptical element 100. EM radiation 104, on the other hand, representslight emitted by optical element 100 that is incident on photo-detector110.

In some embodiments, capacitance detector 120 includes a first voltagesource 170, which is configured to generate and output a voltage V_(C)for performing capacitance measurements. First voltage source 170 canoperate in conjunction with second voltage source 172, which is used togenerate and output a voltage V_(M) to cause first plate 102 a andsecond plate 102 b to modulate. Voltage sources 170 and 172 may be inelectrical communication with first plate 102 a, however, alternatively,voltage sources 170 and 172 may be in electrical communication withsecond plate 102 b. In some embodiments, voltage V_(C) operates at ahigher frequency than voltage V_(M). For example, voltage V_(C) mayoperate at 10,000 Hz or more, whereas voltage V_(M) may operate at afrequency of 1,000 Hz or more. In some embodiments, voltage V_(C)provided by capacitance detector 120 acts as a superimposed voltage withrespect to voltage V_(C) applied to optical element 100 by MEMS drivingcircuit 140 to cause the parallel plates to modulate. In someembodiments, voltage V_(M) is greater in magnitude than voltage V_(C)such that, when measuring the mutual capacitance across plates 102 a,102 b, voltage V_(M) has a negligible effect on the modulation. In someembodiments, a single voltage source is used as opposed to voltagesources 170 and 172. For example, two separate voltages may besuperimposed on top of one another and output as a single voltage. Insome embodiments, the time-dependent voltage (or voltages) are output toplates 102 a or 102 b, and a different, constant voltage is applied tothe other of plates 102 a and 102 b.

Voltage sources 170 and 172, which may be electrically connected inseries to one another, and in parallel to a high-pass filter 160.High-pass filter 160 may be electrically connected to a trigger signalgenerator 162. In some embodiments, trigger signal generator 162generates a trigger signal provided to photo-detector 110 to causephoto-detector 110 to measure an intensity of incident light, asdescribed above. The trigger signal produced by trigger signal generator162 can also be used to facilitate capacitance detector 120 measuringthe instantaneous mutual capacitance across plates 102 a and 102 b. Bygenerating the trigger signal for measuring the intensity of theincident light at photo-detector 110 and measuring the instantaneousmutual capacitance of optical element 100, the two measurement eventscan occur simultaneously, or substantially simultaneous. In someembodiments, processors 130 are configured to generate the triggersignal instead of, or in conjunction with, trigger signal generator 162.In FIG. 1B, the trigger signal generated by trigger signal generator 162may be based on voltage V_(C) and voltage V_(M). Processors 130 can beused to generate arbitrary trigger signals that are not necessarilyrelated to voltage V_(C) and voltage V_(M), which may be used fortriggering purposes.

In some embodiments, capacitance detector 120 includes a current/chargeintegrator 164, which is in electrical communication with second plate102 b of optical element 100. Current/charge integrator 164 additionallycan be in electrical communication with the trigger signal produced bytrigger signal generator 162. Current/charge integrator 164 can beconfigured to measure a total amount of charge across plates 102 a, 102b by performing a time integration of the current/charge measured duringa measurement cycle. In some embodiments, a signal conditioner 168 maybe in electrical communication with trigger signal generator 162 andcurrent/charge integrator 164. Signal conditioner 168 may be configuredto transform a signal from a first form to a second form. Capacitancedetector 120 may also include a sampler 166 which is in electricalcommunication with current/charge integrator 164 and another instance ofsignal conditioner 168. In some embodiments, sampler 166 may beconfigured to perform the measurements of the instantaneous mutualcapacitance across plates 102 a and 102 b for each measurement event,and output the measured capacitance values to processors 130. Forexample, sampler 166 may measure the capacitance across plates 102 a,102 b at a predetermined sampling frequency (e.g., 1,000 Hz, 5,000 Hz,10,000 Hz, etc.), and may output the measured capacitance value.Together with the measured intensity, performed by photo-detector 110 atthe predetermined sampling frequency, processors 130 may resolve thespectrum of the incoming EM radiation 102.

FIG. 1C illustrates an example of current detector 125 of the system ofFIG. 1A, in accordance with various embodiments. For simplicity, and toavoid obfuscating components, capacitance detector 120 is notillustrated. Similar to FIG. 1B, FIG. 1C depicts a system 30 includingoptical elements 100, photo-detector 110, processors 130, and MEMSdriving circuit 140. In some embodiments, system 30 includes currentdetector 125, which include similar components as capacitance detector120 of FIG. 1B.

Current detector 125 may include current measuring electronics 180configured to measure a current output by optical element 100. A currentgoing into optical element 100 may be monitored as plates 102 a and 102b are modulated by voltage V_(M). In some embodiments, voltage source170 is not included for performing capacitance measurements as, in FIG.1C, current is instead measured. For example, capacitance detector 120of FIG. 1B includes current measuring electronics 180. In someembodiments, a current I_IN is input to first plate 102 a, and a currentI_OUT is output by second plate 102 b. The modulation in the current,which can be determined based on current I_OUT may then be used inconjunction with the intensity measurements detected by photo-detector110 to resolve the spectrum of incoming EM radiation 102. Currentdetector 125 can use the measured current values to determine a value ofthe capacitance across first plate 102 a and second plate 102 b. Then,using the capacitance values and the intensity values determined byphoto-detector 110, gap values (e.g., a size of the gap between firstplate 102 a and second plate 102 b) can be determined and used toresolve the spectrum of incoming EM radiation 102. In some embodiments,the current is a function of time. For example, the current may betime-dependent (e.g., sinusoidal), which allows for the capacitancevalues to be derived from the measured current values.

FIG. 2 illustrates an example of a data structure 200 stored in memory150 including measured intensities and capacitances, in accordance withvarious embodiments. Although not depicted in FIG. 2 , an additionalcolumn including measured currents can also be included in datastructure 200, or in another data structure stored by memory 150. Insome embodiments, data structure 200 includes data fields 202, 204, and206. Data field 202 may include data values for a signal identifier ofeach trigger signal sent from processors 130 to photo-detector 110 andcapacitance detector 120. In some embodiments, signals S1-SN are sent,consecutively, at a predefined temporal interval. For example, signal S1may be sent at a time t1, signal S2 may be sent at a time t2, signal S3may be sent at a time t3, and so on. In this example, time t2 may be Δtseconds after time t1, and time t3 may be Δt seconds after time t2. Datafield 204 may include data values of an intensity measurement detectedby photo-detector 110 in response to receiving a corresponding triggersignal from processors 130. For example, in response to receiving signalS1, photo-detector 110 may measure an instantaneous intensity of emittedEM radiation 104 from optical element 100 that is incident onphoto-detector 110, record the measured intensity, and provide themeasured intensity to memory 150 whereby the measured intensity can bestored as a data value in data field 204 in association with thecorresponding digital signal (e.g., intensity measurement IN_1corresponding to digital signal S1). Data field 206 may include datavalues of a capacitance measured by capacitance detector 120 in responseto receiving a corresponding signal from processors 130. For example, inresponse to receiving signal S1, capacitance detector 120 may measure aninstantaneous capacitance of optical element 100, record the measuredcapacitance, and provide the measured capacitance to memory 150 wherebythe measured capacitance can be stored as a data value in data field 206in association with the corresponding digital signal (e.g., capacitancemeasurement C1 corresponding to digital signal S1). Furthermore, in someembodiments, data structure 200 may include an additional columnindicated measured current values (e.g., via current detector 125).Using the measured current values, capacitance measurements C1-CN may beobtained.

FIG. 3 illustrates an example of an optical element 300, in accordancewith various embodiments. In some embodiments, optical element 300represents an example of optical element 100 from FIG. 1 . For instance,optical element 300 may be a Fabry-Perot interferometer, however othertypes of interferometers may be used. In some embodiments, opticalelement 300 includes one or more components, such as a first plate 302 aand a second plate 302 b. Optical element 300 may be configured suchthat first plate 302 a and second plate 302 b are substantially parallelto one another. In other words, a distance d of a gap 306 between aninner surface 308 a of first plate 302 a and an inner surface 308 b ofsecond plate 302 b is substantially constant along a length of plates302 a and 302 b. For example, plates 302 a and 302 b are maintained adistance d±δd, where δd/d is approximately 0. In some embodiments,distance d is can be between 500 Angstroms and 1 micron in size, howeverdistances less than 500 Angstroms or greater than 1 micron can also beused (e.g., approximately 0-2 microns). In some embodiments, first plate302 a and second plate 302 b are formed of one or more conductive and/ortransparent materials. For example, first plate 302 a and second plate302 b may be formed of Indium Tin Oxide (ITO), however other materials,such as, but not limited to, Fluorine doped Tin Oxide (FTO), doped ZincOxide, or other transparent conductive oxides, may be used. In someembodiments, as described below, first plate 302 a and second plate 302b are formed on one or more non-conductive and transparent materials.

In some embodiments, a thin-layer of reflective material is deposited oraffixed to inner surface 308 a of first plate 302 a and inner surface308 b of second plate 302 b. For example, layer 304 a, which may be areflective layer, may be affixed to inner surface 308 a of first plate302 a and layer 304 b, which may also be a reflective layer, may beaffixed to inner surface 308 b of second plate 302 b. Gap 306 refers tothe distance (e.g., distance d) between layer 304 a and layer 304 b. Insome embodiments, layers 304 a and 304 b are formed of a reflectivematerial, such as a thin metallic film or a dielectric mirror. Thecomposition of layers 304 a and 304 b may depend on the composition ofplates 302 a and 302 b. For example, if plates 302 a and 302 b areformed of glass (or other substrates having high-transmissivity), thenlayers 304 a and 304 b may be dielectric mirrors deposited on plates 302a and 302 b. As another example, a combination of a metallic film and adielectric mirror may be used to form layers 304 a and 304 b.Alternatively, in some embodiments, plates 302 a and 302 b do notinclude layers 304 a and 304 b, respectively.

In some embodiments, gap 306 may be varied. For instance, processors130, described previously with respect to FIG. 1 , may be configured togenerate and output a driving signal, which is provided to MEMS drivingcircuit 140. In response to receiving the driving signal, MEMS drivingcircuit 140 may produce and apply a varying electrical signal to plates302 a and 302 b to cause plates 302 a and 302 b to be attracted to oneanother. For example, the varying electric signal may be a voltage,current, or charge, and application of the varying electrical signal toplates 302 a and 302 b, if plates 302 a and 302 b are formed of aconductive material, can cause plates 302 a and 302 b to becomeattracted to one another, thereby decreasing distance d of gap 306. Theattraction of plates 302 a and 302 b causes gap 306 between plates 302 aand 302 b to decrease such that distance d becomes smaller. In someembodiments, distance d between plates 302 a and 302 b is 5,000±500Angstroms. However, distance d may be other distances, such as, but notlimited to, between 1,000-2,000 Angstroms, 2,000-4,000 Angstroms,3,000-7,000 Angstroms, 5,000-10,000 Angstroms, approximately 2 microns,or other ranges. After varying electric signal is removed or otherwiseno longer applied to plates 302 a and 302 b, plates 302 a and 302 b mayreturn to their respective original positions, as described in greaterdetail below with respect to FIGS. 7A and 7B.

In some embodiments, optical element 100, 300 includes anelectromechanical actuator, such as a piezoelectric actuator. Thepiezoelectric actuator may be used to cause plates 302 a and 302 b tomove closer to one another or apart from one another in response to amechanical adjustment.

In some embodiments, optical element 300 is designed such that arelatively narrow range of wavelengths of incoming EM radiation (e.g.,EM radiation 102) are able to pass through, as detailed below withrespect to FIG. 4 , and the incoming EM radiation is periodic inwavenumber. For example, FIG. 4 includes an example of a plot 400depicting a transmission window for an example optical element, such asoptical element 300 of FIG. 3 . As seen in FIG. 4 , plot 400 includestwo peaks corresponding to two wavenumbers of a particular wavelength ofincoming EM radiation. As distance d of gap 306 is varied, the peaks ofeach will move to the right or left. The sharpness of each of the peaksdepicted in plot 400 can depend on the design of layers 304 a and 304 b.For example, each peak can vary in shape and size depending on whetherlayers 304 a and 304 b are formed using metallic films, dielectricmirror stacks, or other materials/compositions. Additionally, theposition of the peaks, with respect to wavenumber, will depend ondistance d of gap 306.

FIG. 5 illustrates another example of an optical element 500, inaccordance with various embodiments. Similar to optical element 300 ofFIG. 3 , optical element 500 includes a first plate 502 a and a secondplate 502 b, which may be the same or similar to first plate 302 a andsecond plate 302 b of FIG. 3 , respectively. First plate 502 a andsecond plate 502 b may or may not be formed of a non-conductivematerial. Optical element 500 also includes a first layer 504 a affixedto an inner surface 508 a of first plate 502 a and a second layer 504 baffixed to an inner surface 508 b of second plate 502 b. Layers 504 a,504 b and inner surfaces 508 a, 508 b may be the same or similar tolayers 304 a, 304 b and inner surfaces 308 a, 308 b, respectively, ofFIG. 3 , and the previous description may apply. Further still, in someembodiments, plates 502 a and 502 b, including layers 504 a and 504 baffixed to inner surfaces 508 a and 508 b, respectively, are separatedby a gap 506 of distance d.

In some embodiments, optical element 500 includes a dielectric material510 disposed in gap 506. For example, dielectric material 510 may beformed of a liquid crystal. In some embodiments, application of avarying electrical signal, such as a voltage, current, or charge, todielectric material 510 causes an index of refraction of dielectricmaterial 510 to vary. The net result can be substantially equivalent tochanging distance d of gap 506 (such as described above for FIG. 3 )without altering the actual distance d. The optical length of an opticalelement is a function of the distance between the parallel plates andthe index of refraction of the material located in-between the parallelplates. For optical element 300 of FIG. 3 , the material located betweenthe parallel plates (e.g., plates 302 a, 302 b) is air, which has anindex of refraction of 1.00. Therefore, the optical length of opticalelement 300 is directly proportional to distance d of gap 306. However,alternatively, if the distance is held fixed, such as for opticalelement 500 of FIG. 5 , then the optical length of optical element 500can be varied by varying the index of refraction of the material betweenplates 502 a, 502 b. To vary the index of refraction, appropriatedielectric material 510 can be injected into gap 506, and the varyingelectrical signal can be applied to dielectric material 510. In someembodiments, the instantaneous capacitance of optical element 500 ismeasured to obtain a value of the dielectric constant of dielectricmaterial 510 at that particular measurement instance, a voltage appliedto optical element 500 at that particular measurement instance, or both.

FIGS. 6A and 6B illustrate another example of an optical element 600from side-view and a top-view, respectively, in accordance with variousembodiments. In FIG. 6A, the side view of optical element 600 isdepicted, including a first plate 602 a and a second plate 602 b, afirst layer 604 a affixed to an inner surface 608 a of first plate 602a, and a second layer 604 b affixed to an inner surface 608 b of secondplate 602 b. Plates 602 a, 602 b and layers 604 a, 604 b of opticalelement 600 may be the same or similar to plates 302 a, 302 b and layers304 a, 304 b of optical element 300, with the exception that plates 602a, 602 b may be formed of a non-conductive material. In someembodiments, conductive elements 610 a and 610 b are placed along anexterior of plates 602 a and 602 b. In response to application of avarying electrical signal (e.g., a time-dependent a voltage, current, orcharge) to conductive elements 610 a and 610 b, an attractive force isproduced that causes plates 602 a, 602 b to move closer to one another,thereby decreasing a distance d of gap 606. In response to no longerapplying the voltage, current, or charge to conductive elements 610 aand 610 b, the attractive force is also removed, thereby allowing plates602 a, 602 b to return to their original position.

In FIG. 6B, conductive elements 610 a and 610 b are depicted as beingrectangular in shape and positioned at an exterior surface of plates 602a and 602 b, respectively. However, alternative configurations are alsopossible. For example, conductive elements 610 a and 610 b may becircular (or “ring”-like) and may surround plates 602 a and 602 b. Insome embodiments, only a single conductive element or more than twoconductive elements may be used. For example, instead of conductiveelement 610 a being placed towards a “top” end of plates 602 a and 602b, and conductive element 610 b being placed towards a “bottom” end ofplates 602 a and 602 b, a single conductive element positionedequatorially may be used.

FIGS. 7A and 7B illustrate an example of systems 700, 750, respectively,for performing interferometric spectroscopy, in accordance with variousembodiments. In some embodiments, system 700 includes optical element100, photo-detector 110, capacitance detector 120, processors 130, MEMSdriving circuit 140, or other components. For instance, current detector125 may also be included in systems 700 and 750. For example, systems700 and 750 may include current detector 125 in addition to, or in lieuof, capacitance detector 120. However, to avoid obfuscating elements,current detector 125 is not illustrated in systems 700 and 750. Forexample, instead of including capacitance detector 120, systems 700 and750 may include current detector 125. In some embodiments, systems 700and 750 may include both capacitance detector 120 and current detector125. In some embodiments, optical element 100 may be the same or similarto optical element 300, however other configurations (e.g., opticalelements 500, 600), may be used.

In FIG. 7A, optical element 100 may include a first plate 702 a and asecond plate 702 b, which are substantially parallel to one another, andwhich have a first layer 704 a and a second layer 704 b affixed,respectively, to inner surface 708 a of first plate 702 a and innersurface 708 b of second plate 702 b. In some embodiments, plates 702 a,702 b and layers 704 a, 704 b may be the same or similar to plates 302a, 302 b and layers 304 a, 304 b of optical element 300, and theprevious description may apply. For example, plates 702 a, 702 b may beformed of a conductive material such that plates 702 a, 702 b form aparallel plate capacitor. In some embodiments, optical elements 100 ofFIG. 7 includes spacers 710 located on a lateral end of plates 702 a,702 b, which are configured to suspend first plate 702 a including firstlayer 704 a above second plate 702 b including second layer 704 b tocreate a gap 706 having a distance d1. In some embodiments, gap 706 maybe a distance d1 when the varying electrical signal (e.g., voltage,current, or charge) is applied to optical element 100.

In some embodiments, system 700 includes a substrate 712 on whichoptical element 100 is disposed. Substrate 712 may be formed of atransparent material, such as glass, such that EM radiation emitted fromoptical element 100 (e.g., EM radiation 104) is able to pass throughsubstrate 712 and incident photo-detector 110. In some embodiments,substrate 712 is configured to shape or focus the EM radiation outputfrom optical element 100 towards photo-detector 110. For example,substrate 712 may act as a lens to focus EM radiation 104 to incidentphoto-detector 110. In some embodiments, substrate 712 is configured toprovide mechanical support and stability for optical element 100, andsystem 700 may include an additional lens disposed between substrate 712and photo-detector 110 to focus the EM radiation output from opticalelement 100 towards photo-detector 110.

In some embodiments, optical element 100 (and similarly optical elements300, 500, 600), may be fabricated by depositing, patterning, and etchingvarious films and materials on a substrate (e.g., substrate 712). Gap706 may be formed by first depositing a sacrificial layer in its placeand then etching away the sacrificial layer. This process may be thesame or similar to known MEMS fabrication techniques and is described inmore detail below with respect to FIG. 8 .

In some embodiments, a varying electrical signal is applied to opticalelement 100. The varying electrical signal may be a voltage, a current,or a charge. In some embodiments, the varying electrical signal isgenerated by MEMS driving circuit 140 in response to receipt of adriving signal from processors 130. The varying electrical signal mayinclude different phases that apply different signals. For example,varying electrical signal may be a time-dependent signal, formed as astep-function, a sinusoidal function, or another time-dependentfunction. In this example, during a first phase of the varyingelectrical signal, a first electrical signal is applied to opticalelement 100 (e.g., 0 V, in case of voltage) whereas during a secondphase, a second electrical signal is applied to optical element 100(e.g., +/−3 V, in case of voltage).

As seen in FIG. 7B, when the varying electrical signal is applied tooptical element 100 (e.g., a voltage applied between plates 702 a and702 b when plates 702 a and 702 b are conductive), an electrostaticforce may be created which causes plates 702 a and 702 b to be attractedto one another. The attractive electrostatic force causes plate 702 a todeform, as seen in FIG. 7B, thereby decreasing gap 706 such that thedistance between plates 702 a and 702 b decreases from distance d1 seenin FIG. 7A to distance d2 of FIG. 7B. As mentioned above, plate 702 amay be suspended above second plate 702 b by spacers 710 such that firstplate 702 a, as well as first layer 704 a, may deform as a result of theattractive electrostatic force. The deformation of first plate 702 a andfirst layer 704 a may result in the changed distance d1 of gap 706. Insome embodiments, when the input signal is removed, the attractiveelectrostatic force between first plate 702 a and second plate 702 balso is removed, and first plate 702 a and first layer 704 a may returnto their original position as seen in FIG. 7A. Persons of ordinary skillin the art will recognize that, in some embodiments, an input signal mayalternatively be applied to cause first plate 702 a and first layer 704a to stay in a first position, such as that shown in FIG. 7A, wherebygap 706 has a first distance d1, and removal of the input signal causesfirst plate 702 a and first layer 704 a to deform to a second positionas seen in FIG. 7B. Alternative input signal configurations are alsopossible, and the aforementioned are used as illustrative examples. Whenthe attractive electrostatic force causes first plate 702 a and firstlayer 704 a to deform, a tension is also created. This is a similareffect as that of a compressed spring, i.e., the restoring force of thespring due to compression of the spring seeks to cause the spring tostop being compressed. In some embodiments, the mass of first plate 702a and first layer 704 a may cause a time lag between an instant when thevarying electrical signal is removed from optical element 100 and whenfirst plate 702 a and first layer 704 a return to the original position(e.g., as seen in FIG. 7A). The time lag may occur due to squeezed aireffect of the air present in air gap 706. However, because of the highfrequency with which the capacitance measurements are performed (e.g.,10,000 Hz), any time lag that may occur has negligible effect on thecapacitance measurements of optical element 100. In some embodiments,evacuating all air from optical element 100 is used to rid opticalelement 100 of any time lag and/or unwanted squeezed air affect.

As mentioned previously, in some embodiments, the varying electricalsignal used to cause first plate 702 a and first layer 704 a to deform,thereby varying the distance of gap 706, is a time-dependent signal. Forexample, a sinusoidal signal may be used, having a frequency ω, to applya voltage, current, or charge to optical element 100 and thereby causingthe deformation of first plate 702 a and first layer 704 a. Thus, thevarying electrical signal may be periodically oscillating between afirst input signal value (e.g., voltage +V, in case of voltage) and asecond signal value (e.g., voltage −V) over a time period characterizedby frequency ω. The frequency ω may be, for example, 100 Hz or more, 500Hz or more, 750 Hz or more, 1,000 Hz or more, and the like. Thus, at anygiven time, the value of the input signal applied to optical element 100may vary, and, as a result, a distance of gap 706 at any given time mayalso vary. In some embodiments, the frequency with which plates 702 aand 702 b modulate is smaller than the frequency with which the mutualcapacitance across plates 702 a and 702 b, or the current output byoptical element, is measured. For example, plates 702 a and 702 b may bemodulated at a frequency of 1,000 Hz, whereas capacitance detector 120may be configured to measure the mutual capacitance across plates 702 aand 702 b at a frequency of 100,000 Hz.

In some embodiments, to determine an optical characteristic of opticalelement 100, such as a value (e.g., a distance) of gap 706 at anyinstant, an instantaneous capacitance measurement of optical element 100is obtained. For example, capacitance detector 120 may measure acapacitance across first plate 702 a and second plate 702 b. In someembodiments, to determine an optical characteristic of optical element100, such as a value (e.g., a distance) of gap 706 at any instant, aninstantaneous current measurement of optical element 100 is obtained. Asthe varying electrical signal is time dependent, the currentmeasurements may be used to derive the capacitance, which in turn can beused to derive a size of gap 706 at an instant. Some cases includecapacitance detector 120 measuring an amount of charge drawn by opticalelement 100 (e.g., an effective parallel plate capacitor formed by firstplate 702 a and second plate 702 b) as a function of time. In someembodiments, the capacitance at any instant is a function of gap 706(e.g., the distance between plates 702 a and 702 b). As an example, thedistance of gap 706 may be computed based on an inverse of the measuredcapacitance values. In some embodiments, capacitance detector 120 istriggered to sample (e.g., measure) an instantaneous capacitance ofoptical element 100. For example, processors 130 may generate a triggersignal that causes capacitance detector 120 to measure the capacitanceof optical element 100. In some embodiments, current detector 125 istriggered to sample an instantaneous current output from optical element100. For example, processors 130 may generate a trigger signal thatcauses current detector 125 to measure the current output from opticalelement 100. Using the current measurements, a capacitance of opticalelement 100 may be determined.

Processors 130 may generate and output the trigger signal at apredefined time interval, such as every Δt seconds. For example, as seenabove with reference to FIG. 2 , signal S1 may be a first trigger signaloutput by processors 130 and provided to capacitance detector 120, whichsubsequently measures a capacitance value C1. As another example, signalS1 may be a first trigger signal output by processors 130 and providedto current detector 125, which subsequently measures a value of theoutput current from optical element 100. Additionally, the trigger mayalso be provided to photo-detector 110 to measure an intensity ofincident EM radiation on photo-detector 110. For example, responsive tothe first trigger signal, signal S1, photo-detector 110 measures anintensity IN_1 of EM radiation incident thereon. Furthermore, someembodiments include capacitance detector 120 or current detector 125being used to generate or cause the trigger signal to be generated basedon the voltage applied to plates 702 a and 702 b to cause plates 702 aand 702 b to modulate, as well as the voltage applied to plates 702 aand 702 b to measure the capacitance across them, as detailed above withrespect to FIG. 1B.

Some embodiments include sampling the capacitance values and theintensity values detected by capacitance detector 120 and photo-detector110, respectively, over many cycles of the input signal (e.g., the inputvoltage, current, or charge). Some embodiments include sampling thecurrent values and the intensity values detected by current detector 125and photo-detector 110, respectively, over many cycles of the inputsignal (e.g., the input current). Sampling over a large number of cyclescan improve signal-to-noise ratios (SNR).

As detailed above, optical element 100 may be relatively small in size.For example, optical element 100 may be of the order of a fewmillimeters (e.g., 5 mm by 5 mm by 2 mm). In some embodiments, opticalelement 100 uses electromechanical actuators, such as piezo-electricactuators, to vary gap 706. In such cases, optical element 100, and inparticular plates 702 a, 702 b and layers 704 a, 704 b, are generallymuch larger in dimensions (e.g., of the order of 0.5 inches or greater)and plates 702 a, 702 b are much stiffer. Plates 702 a and 702 b mayalso be formed of a same or similar material, however some cases includeplates 702 a and 702 b being formed of different materials. Furthermore,the correlation between the input signal applied to theelectromechanical actuators and the distance of gap 706 may bedetermined by sampling the time varying input signal applied to theelectromechanical actuators or by directly measuring the capacitance ofoptical element 100 to determine a value of the distance d of gap 706and simultaneously measuring the intensity of the incident EM radiationon photo-detector 110.

In some embodiments, the aforementioned devices and techniques may beimplemented in an image capture device, such as a camera. For example, ahigh-speed camera may operate as a spectrometer camera where every pixelof the imager is capable of resolving an entire, or a portion of,spectrum of the incoming EM radiation (e.g., light). By applying theinput signal such that the driving frequency of the input signal variesperiodically, gap 706 can change in time (e.g., distance d will vary intime). The trigger signal may be used to simultaneously capture, atdiscrete time intervals, the instantaneous capacitance value of opticalelement 100 and may also simultaneously take a full image frame of theincoming EM radiation 102. As mentioned previously, the incoming EMradiation 102 may reflect or pass through an object with which amaterial composition is to be determined for, or a spectrum of theincoming radiation may be determined. Therefore, in this example, a fullinstantaneous image may be produced for every instantaneous gap 706 ofoptical element 100. In some embodiments, to increase the SNR, thesimultaneous measurements of the capacitance and the intensity of the EMradiation may be repeated over many cycles of the driving input signal.Each pixel of the image may have a signal that is mathematically relatedto the transmission characteristics of optical element 100 and thespectrum of incoming EM radiation 102, and some embodiments includeproducing or resolving a full spectrum of incoming EM radiation 102 fora corresponding pixel. When all pixels are processed this way, a fullspectrometric image can be obtained. In some embodiments, opticalelement 100 and the camera can be driven very fast by appropriate fastelectronics as in a high frame rate camera (e.g., 100 or more frames persecond, 500 or more frames per second, 1000 or more frames per second,and the like) to obtain a very fast spectroscopic image of an object orscene.

FIGS. 8A-8H illustrate an example process for fabricating an opticalelement for performing interferometric spectroscopy, in accordance withvarious embodiments. Each of FIGS. 8A-8H depicts a portion of thefabrication process, however additional steps may be performed inaddition to, or instead of, the described processes.

FIG. 8A illustrates a first step of the example fabrication process.FIG. 8A includes a substrate 802, which is obtained for use forfabricating the interferometer. In some embodiments, substrate 802 isformed of a transparent material. For example, substrate 802 may beformed of glass, Silicon, or other materials. The material selected forsubstrate 802 may depend on the wavelength range to be examined with theinterferometer after being fabricated. For example, if theinterferometer is to be used to examine EM radiation in the visiblewavelength range (e.g., 400-700 nm), then substrate 802 may be formedfrom glass. As another example, if the interferometer is to be used toexamine EM radiation in the infrared wavelength range (e.g., 700 nm-1mm), then substrate 802 may be formed from Silicon.

FIG. 8B includes a first layer 804 deposited on a surface of substrate802. In some embodiments, first layer 804 is a metallic mirror or adielectric mirror. In some embodiments, first layer 804 may be formed ofa transparent conducting material, such as ITO, FTO, or other materials.

FIG. 8C includes a structural material 806 deposited on a surface offirst layer 804 opposite that with which first layer 804 contactssubstrate 802. Structural material 806 can be used to form one or morestructures residing on first layer 804. The structures to be formed canenable the plates of the optical element (e.g., plates 702 a, 702 b) tobe separated by a distance d. Moreover, the structures will allow an airgap to be formed between the plates of the optical element.

FIG. 8D includes structures 808 formed on first layer 804 afterpatterning and etching of structural material 806 is performed. In someembodiments, structures 808 correspond to spacers 710 of FIGS. 7A and7B. A height of structures 808 may be equal to a desired initial size ofthe air gap for optical element 100. For example, a height of structures808 may be equal to distance d. While FIG. 8 depicts two instances ofstructures 808, additional structures may also be included as a resultof the patterning and etching of structural material 806.

FIG. 8E includes a sacrificial layer 810 deposited over structures 808,first layer 804, and substrate 802. Sacrificial layer 810 will beremoved in subsequent process steps to form the air gap. It can also beused to help smooth and normalize a height of a new layer to be added ontop of structures 808 such that the new layer will be substantiallyparallel to first layer 804 and substrate 802.

FIG. 8F shows a planarization process step 812 being performed tosacrificial layer 810. As mentioned above, planarization process step812 can be used to ensure that further layers to be added are parallelwith first layer 804 and substrate 802.

FIG. 8G includes a second layer 814 and a plate 816 deposited onplanarized layers 812 and 808 such that second layer 814 and plate 816are substantially parallel to first layer 804 and substrate 802. In someembodiments, second layer 814 is formed of a substantially similarmaterial as first layer 804. For example, second layer 814 may be ametallic or dielectric mirror. In some embodiments, plate 816 is formedof a substantially similar material as substrate 802. For example, plate816 may be formed of glass or ITO.

FIG. 8H depicts a completed structure where sacrificial layer 810 hasbeen etched away. As a result of the etching, an air gap is now presentin the region between structures 808, first layer 804, and second layer814. This air gap region can allow plate 816 to modulate in response toreceipt of a driving signal, as described above with reference to FIGS.7A and 7B.

FIGS. 9A and 9B illustrate additional example optical elements 900, 950,respectively, for performing interferometric spectroscopy, in accordancewith various embodiments. In some embodiments, optical element 900includes a first plate 902 a and a second plate 902 b. First plate 902 aand second plate 902 b may both be formed from a conductive transparentmaterial. For example, first plate 902 a and second plate 902 b may beformed from ITO. On an inner surface of first plate 902 a may be a firstlayer 904 a and on an inner surface of second plate 902 b may be asecond layer 904 b. Layers 904 a and 904 b may be deposited on plates902 a and 902 b such that layers 904 a and 904 b face one another andare substantially parallel to one another (and plates 902 a and 902 b,respectively). In some embodiments, first layer 904 a and second layer904 b are each formed of a multi-layer mirror, metallic mirror, or acombination thereof.

First plate 902 a and first layer 904 a may be separated from secondplate 902 b and second layer 904 b by spacers 910 forming an air gap906. Air gap 906 may be of a distance d in size when no deformation offirst plates 902 a and first layer 904 a occurs. As mentioned above withrespect to FIGS. 8A-8H, air gap 906 may be formed also as a result ofthe fabrication process to create optical element 900.

In some embodiments, second layer 902 b may reside on a substrate 912,and can provides structural support for optical element 900. Substrate912 may be formed of a transparent material such as glass or Silicon.The particular material used for substrate 912 may depend on thewavelength range of the incident EM radiation to be analyzed. Forexample, for EM radiation in the visible wavelength range (e.g., 400-700nm), substrate 912 may be formed of glass. As another example, for EMradiation in the IR wavelength range (e.g., 700 nm-1 mm), substrate 912may be formed from Silicon.

Many of the elements described above with respect to optical element 900are the same or similar to the corresponding elements described withrespect to optical elements 100, 300, 500, and 600, and some of thedetails have not been reproduced for brevity. However, any of thefeatures mentioned above with respect to optical elements 100, 300, 500,or 600 may also be characteristic of optical element 900.

In some embodiments, optical element 900 further includes conductiveelements, such as conductive elements 912 a and 912 b, located on firstplate 902 a and conductive elements 914 a and 914 b located on secondplate 902 b. Conductive elements 912 a and 912 b, as well as conductiveelements 914 a and 914 b may be located on opposite sides of first plate902 a and second plate 902 b, respectively. For example, conductiveelement 912 a may be located at a first end of first plate 902 a (e.g.,a left side), whereas conductive element 912 b may be located at asecond end of first plate 902 a (e.g., a right side). Similarly,conductive element 914 a may be located at a first end of second plate902 b, while conductive element 914 b may be located at a second end ofsecond plate 902 b. In some embodiments, conductive elements 912 a and912 b are located on an opposite side of first plate 902 a as that offirst layer 904 a. However, conductive elements 914 a and 914 b may belocated on a same side of second plate 902 b as that of second layer 904b. In the latter case, second layer 904 b may reside on only a portionof an upper surface of second plate 902 b such that conductive elements914 a and 914 b also are capable of residing on the upper surface ofsecond plate 904 b. If the plates are circular in shape when viewed fromabove, then the elements 912 a and 912 b are the same elements;similarly 914 a and 914 b are the same in this situation.

Conductive elements 912 a, 912 b, 914 a, and 914 b may each be formed ofa same or similar conductive material to allow electrical access tooptical element 900. For example, conductive elements 912 a, 912 b, 914a, 914 b may be silver, gold, or other conductive materials. Conductiveelements 912 a, 912 b, 914 a, 914 b may also be formed as conductivepads or rings, which may be deposited on a surface of first plate 902 aand second plate 902 b, respectively, during the fabrication process(e.g., as described with respect to FIGS. 8A-8H), or after thefabrication process. Conductive elements 912 a, 912 b, 914 a, 914 b canallow for one or more components of system 10, 20, described above, tobe in electrical communication with optical element 900. For example,voltage source 170 may be in electrical communication with first plate902 a via conductive elements 912 a and 912 b to induce a charge ontofirst plate 902 a. In some embodiments, some or all of conductiveelements 912 a, 912 b, 914 a, 914 b can be in electrical communicationwith current/charge integrator 164 and sampler 166 to facilitatemeasuring a mutual capacitance across plates 902 a and 902 b. Thus, thevarious electrical signals (e.g., a current, voltage, charge) can beinput to optical element 900 via one or more of conductive elements 912a, 912 b, 914 a, 914 b, and, furthermore, one or more measurements(e.g., capacitance measurements, current measurements) can be obtainedvia one or more of conductive elements 912 a, 912 b, 914 a, 914 b. Insome embodiments, the varying input signal used to cause the modulationof plates 902 a and 902 b may be provided to conductive elements 912 a,912 b, 914 a, 914 b via a first set of inputs, whereas the triggersignal with which a current or capacitance is measured using currentdetector 125 or capacitance detector 120, may be provided to conductiveelements 912 a, 912 b, 914 a, 914 b via a second set of inputs. In someembodiments, a constant input signal (e.g., charge, voltage) may beapplied to some of conductive elements 912 a, 912 b, 914 a, 914 b,whereas a varying input signal may be applied to other ones ofconductive elements 912 a, 912 b, 914 a, 914 b.

In some embodiments, one or more of capacitance detector 120, currentdetector 125, processors 130, and MEMS driving circuit 140 areconfigured to provide a varying input signal to conductive elements 912a, 912 b, 914 a, 914 b to cause a distance between plates 902 a and 902b to vary, such as described above with respect to FIGS. 7A and 7B. Forexample, MEMS driving circuit 140 may be configured to generate and/oroutput a varying input signal (e.g., a varying charge, a varyingvoltage, a varying current) that varies over a period of time. As theinput signal varies, an electrostatic force between plates 902 a, 902 b,and layers 904 a, 904 b, changes, which causes a size of air gap 906 tovary. For instance, during a first phase of the varying input signal,the electrostatic force can cause first layer 904 a and first plate 902a to be attracted to second layer 904 a and second plate 902 b, a sizeof air gap 906 decreases. During a second phase of the varying inputsignal, the electrostatic force decreases, and thus first layer 904 aand first plate 902 a are less attracted to second layer 904 a andsecond plate 902 b, thereby causing the size of air gap 906 to increase(or return to a previous position). In some embodiments, MEMS drivingcircuit 140 is configured to apply the varying input signal toconductive elements 912 a and 912 b and apply a constant signal toconductive elements 914 a and 914 b. For example, a constant voltage maybe applied to conductive elements 914 a and 914 b to fix second plate902 b and second layer 904 b at a particular charge or voltage, and thevarying input signal may be applied to conductive elements 912 a and 912b to allow the charge or voltage of first plate 902 a and first layer904 a to vary.

FIG. 9B illustrates another optical element 950. In some embodiments,aspects of the components of optical element 950 are the same or similarto the components of optical element 900, and the previous descriptionsapply.

In some embodiments, optical element 950 includes a first plate 952 a,but does not include a second plate. First plate 952 a may be formedfrom a non-conductive transparent material. For example, first plate 952a may be formed from Silicon Oxide. On an inner surface of first plate952 a may be a first layer 904 a. Opposite first plate 952 a may besubstrate 912, which may include second layer 904 b. Similar to opticalelement 900 of FIG. 9A, layers 904 a and 904 b may be deposited on plate952 a and substrate 912 such that layers 904 a and 904 b face oneanother and are substantially parallel to one another. In someembodiments, first layer 904 a and second layer 904 b are each formed ofa multi-layer mirror, metallic mirror, or a combination thereof.Additionally, first layer 904 a and second layer 904 b may be separatedby spacers 910 to form an air gap 906 having a distance din size.

In some embodiments, optical element 950 further includes conductiveelements, such as conductive elements 962 a and 962 b, located on firstplate 952 a and conductive elements 964 a and 964 b located on substrate912. Conductive elements 962 a and 962 b, as well as conductive elements964 a and 964 b may be located on opposite sides of first plate 952 aand substrate 912, respectively. For example, conductive element 962 amay be located at a first end of first plate 952 a (e.g., a left side),whereas conductive element 962 b may be located at a second end of firstplate 952 a (e.g., a right side). Similarly, conductive element 964 amay be located at a first end of substrate 912, while conductive element964 b may be located at a second end of substrate 912. In someembodiments, conductive elements 962 a and 962 b are located on anopposite side of first plate 952 a as that of first layer 904 a.However, conductive elements 964 a and 964 b may be located on a sameside of substrate 912 as that of second layer 904 b. In the latter case,second layer 904 b may reside on only a portion of an upper surface ofsubstrate 912 such that conductive elements 964 a and 964 b also arecapable of residing on the upper surface of substrate 912. Furthermore,in some embodiments, because no conductive plate is included onsubstrate 912, as was the case in FIG. 9A, a size of conductive elements964 a and 964 b may be larger than a size of conductive elements 914 aand 914 b.

In some embodiments, conductive elements 962 a, 962 b, 964 a, and 964 bare the same or similar to conductive elements 912 a, 912 b, 914 a, and914 b of FIG. 9A. Additionally, or alternatively, conductive elements962 a, 962 b, 964 a, and 964 b may be further configured to facilitatethe modulation of plate 952 a to cause a size of air gap 906 to vary.For example, instead of applying an input electrical signal to theparallel plates to cause one plate to deform thereby decreasing the sizeof air gap 906, such as in the example depicted above with respect toFIGS. 7A and 7B, a current/voltage/charge can be applied to some or allof conductive elements 962 a, 962 b, 964 a, and 964 b to causemodulation of plate 952 a and first layer 904 a, which is describedabove with respect to FIGS. 6A and 6B. Furthermore, in some embodiments,additional conductive elements may be included in optical element 950 inaddition to conductive elements 962 a, 962 b, 964 a, and 964 b such thatsome of the conductive elements facilitate the modulation of first plate952 a and first layer 904 a while others facilitate measurements of themutual capacitance of optical element 950.

FIGS. 10A and 10B illustrate examples of alternate techniques forperforming interferometric spectroscopy, in accordance with variousembodiments. In FIG. 10A, a system including a first plate 1002 a and asecond plate 1002 b is shown. In some embodiments, first plate 1002 aand second plate 1002 b may be part of an interferometer, such as aFabry-Perot interferometer. First plate 1002 a and second plate 1002 bmay form a parallel plate capacitor. System 1000 further includes alight source 1004, such as a light emitting diode (LED), laser or othersource. In some embodiments, light source 1004 is configured to emit abeam of light that will traverse first plate 1002 a and second plate1002 b, and is detectable by photo-detector 110. A positioning of lightsource 1004 and photo-detector 110 can be varied. In some embodimentsthe detector 110 is a linear detector array.

In some embodiments, an interferometric approach can be used to measurea gap between first plate 1002 a and second plate 1002 b. Similar to thesystems described above, a charge, current, or voltage can be applied toplates 1002 a, 1002 b to cause modulation that varies the size of thegap between plates 1002 a, 1002 b. As plates 1002 a, 1002 b modulate,and thus the size of the gap varies, light source 1004 can emit lightwhich can be detected by photo-detector 110. In some embodiments, theintensity of the detected light varies based on a value of the gap(e.g., a distance d between plates 1002 a, 1002 b). Using the intensitymeasurements, which may or may not be taken in conjunction with thecapacitance measurements measuring the mutual capacitance across plates1002 a, 1002 b, a value of the gap between plates 1002 a, 1002 b can beresolved. The measured intensity may correspond to the reflected light.In some embodiments, photo-detector 110 is a linear detector array.

In system 1050 of FIG. 10B, a similar setup is illustrated, with theexception that photo-detector 110 is arranged to be orthogonal to adirection of the light emitted by light source 1004. For instance,system 1050 may include a beam splitter 1006 that causes some of thelight emitted by light source 1004 to be directed toward plates 1002 a,1002 b and to a mirror 1008, while some of the light is directed towardphoto-detector 110.

FIG. 11 illustrates an example flowchart of a process 1100 for obtainingdata for resolving a spectrum of incident light, in accordance withvarious embodiments. In some embodiments, process 1100 begins at step1102. At step 1102, a sampling frequency of a trigger signal is set. Thesampling frequency represents a frequency with which processors 130 maygenerate and output the trigger signal that causes photo-detector 110,capacitance detector 120, and/or current detector 125 to measure aninstantaneous intensity of EM radiation 104 emitted from optical element100 and incident on photo-detector 110, measure an instantaneouscapacitance across parallel plates of optical element 100 (e.g., plates102 a, 102 b), and/or measure an instantaneous current drawn by opticalelement 100, respectively. As an example, the sampling frequency may be100 Hz or greater, 500 Hz or greater, 1,000 Hz or greater, etc. Aftersetting the sampling frequency, the trigger signal may be sentsimultaneously to photo-detector 110 and capacitance detector 120. Insome embodiments, capacitance detector 120 is configured to measure theinstantaneous capacitance of a proxy element, such as conductiveelements 610 a, 610 b of FIGS. 6A and 6B, conductive elements 912 a, 912b, 914 a, 914 b of FIG. 9A, or conductive elements 962 a, 962 b, 964 a,964 b of FIG. 9B.

At step 1104, a value of a capacitance of optical element 100 is sampledat the sampling frequency. In some embodiments, capacitance detector 120is configured to measure an instantaneous capacitance value of opticalelement 100 in response to receipt of a trigger signal from processors130. For example, capacitance detector 120 may measure a capacitancevalue C1 between plates 702 a, 702 b in response to receiving a triggersignal S1. As another example, capacitance detector 120 may measure acapacitance value of conductive elements 912 a, 912 b, 914 a, 914 b ofFIG. 9A. Alternatively, a value of the current drawn by optical element100 is sampled at the sampling frequency, and the capacitance of opticalelement 100 may be determined based on the sampled current. In someembodiments, current detector 125 is configured to measure aninstantaneous current value of optical element 100 in response toreceipt of a trigger signal from processors 130.

At step 1106, the sampled capacitance values are transformed intotransformation values. For instance, the transformation values canrepresent gap values. In some embodiments, the sampled capacitancevalues, such as capacitance values C1-CN of FIG. 2 , is used todetermine values of gap 706. As mentioned previously, the capacitance ofoptical element 100 is proportional to distance d of gap 706. In someembodiments, processors 130 is configured to retrieve the measuredcapacitance values (e.g., capacitance values C1-CN) stored in memory 150(or directly from capacitance detector 120) and transform eachcapacitance value into a gap value or distance of gap 706.

At step 1108, which is performed simultaneously with step 1104, anintensity of EM radiation transmitted through optical element 100 issampled at the sampling frequency. In some embodiments, photo-detector110 is configured to measure an intensity of the EM radiationtransmitted through optical element 100 that is incident onphoto-detector 110 in response to the trigger signal from processors130. For example, photo-detector 110 may measure an intensity IN_1 ofthe emitted EM radiation from optical element 100 in response toreceiving trigger signal S1.

At step 1110, the gap values and the intensity values are stored. Forexample, the gap values and the intensity values may be stored in memory150, such as in data structure 200. The gap values and the intensityvalues may then be used to resolve a spectrum of the EM radiation (e.g.,EM radiation 102) incident on optical element 100.

The reader should appreciate that the present application describesseveral independently useful techniques. Rather than separating thosetechniques into multiple isolated patent applications, applicant hasgrouped these techniques into a single document because their relatedsubject matter lends itself to economies in the application process. Butthe distinct advantages and aspects of such techniques should not beconflated. In some cases, embodiments address all of the deficienciesnoted herein, but it should be understood that the techniques areindependently useful, and some embodiments address only a subset of suchproblems or offer other, unmentioned benefits that will be apparent tothose of skill in the art reviewing the present disclosure. Due to costsconstraints, some techniques disclosed herein may not be presentlyclaimed and may be claimed in later filings, such as continuationapplications or by amending the present claims. Similarly, due to spaceconstraints, neither the Abstract nor the Summary sections of thepresent application should be taken as containing a comprehensivelisting of all such techniques or all aspects of such techniques.

It should be understood that the description and the drawings are notintended to limit the present techniques to the particular formdisclosed, but to the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the present techniques as defined by the appended claims.Further modifications and alternative embodiments of various aspects ofthe techniques will be apparent to those skilled in the art in view ofthis description. Accordingly, this description and the drawings are tobe construed as illustrative only and are for the purpose of teachingthose skilled in the art the general manner of carrying out the presenttechniques. It is to be understood that the forms of the presenttechniques shown and described herein are to be taken as examples ofembodiments. Elements and materials may be substituted for thoseillustrated and described herein, parts and processes may be reversed oromitted, and certain features of the present techniques may be utilizedindependently, all as would be apparent to one skilled in the art afterhaving the benefit of this description of the present techniques.Changes may be made in the elements described herein without departingfrom the spirit and scope of the present techniques as described in thefollowing claims. Headings used herein are for organizational purposesonly and are not meant to be used to limit the scope of the description.

As used throughout this patent application, the word “may” or “can” isused in a permissive sense (i.e., meaning having the potential to),rather than the mandatory sense (i.e., meaning must). The words“include”, “including”, and “includes” and the like mean including, butnot limited to. As used throughout this application, the singular forms“a,” “an,” and “the” include plural referents unless the contentexplicitly indicates otherwise. Thus, for example, reference to “anelement” or “a element” includes a combination of two or more elements,notwithstanding use of other terms and phrases for one or more elements,such as “one or more.” The term “or” is, unless indicated otherwise,non-exclusive. Limitations as to sequence of recited steps should not beread into the claims unless explicitly specified. Features describedwith reference to geometric constructs, like “parallel,” should beconstrued as encompassing items that substantially embody the propertiesof the geometric construct. The terms “first”, “second”, “third,”“given” and so on, if used in the claims, are used to distinguish orotherwise identify, and not to show a sequential or numericallimitation.

The present techniques will be better understood with reference to thefollowing enumerated embodiments:

-   A1. A system for performing time-resolved interferometric    spectroscopy on incoming light, comprising: one or more optical    elements that, upon application of a varying input signal thereto,    cause a change to an optical characteristic of the one or more    optical elements, thereby resulting in a changing interference    pattern produced by the incoming light incident on the one or more    optical elements; a photo-detector configured to detect an intensity    of light output from the one or more optical elements during    application of the varying input signal; a capacitance detector    configured to detect a capacitance associated with the optical    characteristic during the application of the varying input signal;    and one or more processors configured to: obtain, from the    capacitance detector, a plurality of capacitance values representing    the capacitance of the one or more optical elements, obtain, from    the photo-detector, a plurality of signal values representing the    intensity of the light output from the one or more optical elements,    and generate a plurality of transformation values respectively based    on the plurality of capacitance values.-   A2. The system of embodiment A1, wherein the one or more optical    elements comprise: a first plate and a second plate disposed    parallel to the first plate such that a gap between the first plate    and the second plate is formed, wherein the optical characteristic    comprises a size of the gap which changes as a result of the    application of the varying input signal.-   A3. The system of embodiment A2, wherein the one or more processors    are further configured to: allow selection of a wavelength of the    incoming light for detection; and determine a presence of the    wavelength of the incoming light using some of the plurality of    transformation values and some of the plurality of signal values.-   A4. The system of embodiment A2, wherein the one or more processors    are further configured to: allow selection of a plurality of    wavelengths of the incoming light for detection; and determine a    presence of the plurality of wavelengths of the incoming light at    the plurality of wavelengths using some of the plurality of    transformation values and some of the plurality of signal values.-   A5. The system of embodiment A2, wherein: a metallic film or    dielectric material is disposed on an inner surface of each of the    first plate and the second plate; and each of the first plate and    the second plate are formed of glass.-   A6. The system of embodiment A2, wherein: the first plate is a first    conductive plate formed of a conductive transparent material; the    second plate is a second conductive plate formed of the conductive    transparent material; and multi-layer thin films forming a    reflective surface are disposed on an inner surface of each of the    first conductive plate and the second conductive plate.-   A7. The system of embodiment A2, wherein: the first plate is affixed    to a substrate and the second plate is suspended above the first    plate at a first distance; the varying input signal comprises a    first electrical signal applied to the one or more optical elements    during a first phase and a second electrical signal applied to the    one or more optical elements during a second phase; during the first    phase, application of the first electrical signal causes the second    plate to deform thereby decreasing a distance between the first    plate and the second plate from the first distance to a second    distance; and during second phase, application of the second    electrical signal causes the second plate to return to a starting    position prior to the first electrical signal being applied such    that the distance between the first plate and the second plate is    the first distance.-   A8. The system of any one of embodiments A1-A7, wherein the one or    more optical elements comprise parallel plates, the system further    comprising: a driving circuit configured to: generate the varying    input signal; and provide the varying input signal to the one or    more optical elements to cause the change to the optical    characteristic of the one or more optical elements, wherein the    optical characteristic comprises a distance between the parallel    plates.-   A9. The system of embodiment A8, wherein the varying input signal    comprises one of a time-dependent voltage, a time-dependent current,    or a time-dependent charge.-   A10. The system of embodiment A8, wherein the distance between the    parallel plates is between 500 Angstroms and 1 micron.-   A11. The system of embodiment A1-A10, wherein the one or more    optical elements are disposed on a single chip that forms a    micro-electromechanical (MEMS) device.-   A12. The system of embodiment A11, wherein: a width of the chip is    less than or equal to 10 millimeters (mm); a length of the chip is    less than or equal to 10 mm; and a height of the chip is less than    or equal to 5 mm.-   A13. The system of embodiment A11, wherein: the one or more optical    elements comprise a Fabry-Perot interferometer including a first    plate and a second plate; one or more conductive elements are    coupled to each of the first plate and the second plate; and the one    or more conductive elements are configured to at least one of:    provide a trigger signal to the capacitance detector and the    photo-detector to cause the capacitance detector and the    photo-detector to measure an instantaneous mutual capacitance across    the first plate and the second plate; provide the varying input    signal to at least one of the first plate or the second plate to    cause a modulation of the first plate, the second plate, or the    first plate and the second plate; and provide data to the    capacitance detector representing the instantaneous mutual    capacitance, wherein the plurality of capacity values are generated    based on the data.-   A14. The system of embodiment A13, wherein the one or more    conductive elements are located exterior to the first plate and the    second plate such that, during application of the varying input    signal, a force causes the gap separating the first plate and the    second plate to vary.-   A15. The system of any one of embodiments A1-A14, wherein the one or    more processors are further configured to: generate a trigger signal    operable to simultaneously trigger (i) the photo-detector to detect    the intensity of the light output from the one or more optical    elements and (ii) the capacitance detector to detect the capacitance    of the one or more optical elements; and send the trigger signal to    the photo-detector and the capacitance detector at a frequency of    10,000 Hz or greater.-   A16. The system of any one of embodiments A1-A15, wherein the one or    more optical elements comprise: a first plate and a second plate    disposed parallel to the first plate such that a gap between the    first plate and the second plate is formed; a liquid crystal    material is deposited in the gap between the first plate and the    second plate; the optical characteristic comprises a dielectric    constant of the liquid crystal material; and a value of the    dielectric constant is proportional to a value of the varying input    signal.-   A17. The system of embodiment A16, wherein the one or more    processors are further configured to: generate a plurality of    dielectric values respectively based on the plurality of capacitance    values, wherein the plurality of transformation values comprise a    plurality of dielectric values of the liquid crystal material.-   A18. The system of any one of embodiments A1-A17, wherein the one or    more optical elements are integrated into an image capture device    for determining the spectrum of the incoming light incident on the    pixel array, on a pixel-by-pixel basis.-   B1. A method for operating on incoming light, the method being    implemented by one or more processors executing computer program    instructions, the method comprising: obtaining, from a capacitance    detector configured to detect a capacitance associated with an    optical characteristic of one or more optical elements during    application of a varying input signal, a plurality of capacitance    values representing the capacitance of the one or more optical    elements, wherein upon application of the varying input signal, the    one or more optical elements cause a change to the optical    characteristic thereby resulting in a changing interference pattern    produced by incoming light incident on the one or more optical    elements; obtaining, from a photo-detector configured to detect an    intensity of light output from the one or more optical elements    during application of the varying input signal, a plurality of    signal values representing the intensity of the light output from    the one or more optical elements; and generating a plurality of    transformation values respectively based on the plurality of    capacitance values, wherein the plurality of transformation values    and the plurality of signal values are used to determine a spectrum    of the incoming light.-   B2. The method of embodiment B1, wherein the one or more optical    elements comprise: a first plate and a second plate disposed    parallel to the first plate such that a gap between the first plate    and the second plate is formed, wherein the optical characteristic    comprises a size of the gap which changes as a result of the    application of the varying input signal.-   B3. The method of embodiment B2, further comprising: allowing    selection of a wavelength of the incoming light for detection; and    determining a presence of the wavelength of the incoming light using    some of the plurality of transformation values and some of the    plurality of signal values.-   B4. The method of embodiment B2, further comprising: allowing    selection of a plurality of wavelengths of the incoming light for    detection; and determining a presence of the plurality of    wavelengths of the incoming light at the plurality of wavelengths    using some of the plurality of transformation values and some of the    plurality of signal values.-   B5. The method of embodiment A2, wherein: a metallic film or    dielectric material is disposed on an inner surface of each of the    first plate and the second plate; and each of the first plate and    the second plate are formed of glass.-   B6. The method of embodiment B2, wherein: the first plate is a first    conductive plate formed of a conductive transparent material; the    second plate is a second conductive plate formed of the conductive    transparent material; and multi-layer thin films forming a    reflective surface are disposed on an inner surface of each of the    first conductive plate and the second conductive plate.-   B7. The method of embodiment A2, wherein: the first plate is affixed    to a substrate and the second plate is suspended above the first    plate at a first distance; the varying input signal comprises a    first electrical signal applied to the one or more optical elements    during a first phase and a second electrical signal applied to the    one or more optical elements during a second phase; during the first    phase, application of the first electrical signal causes the second    plate to deform thereby decreasing a distance between the first    plate and the second plate from the first distance to a second    distance; and during second phase, application of the second    electrical signal causes the second plate to return to a starting    position prior to the first electrical signal being applied such    that the distance between the first plate and the second plate is    the first distance.-   B8. The method of any one of embodiments B1-B7, wherein the one or    more optical elements comprise parallel plates, further comprising:    generating, via driving circuit, the varying input signal; and    providing the varying input signal to the one or more optical    elements to cause the change to the optical characteristic of the    one or more optical elements, wherein the optical characteristic    comprises a distance between the parallel plates.-   B9. The method of embodiment B8, wherein the varying input signal    comprises one of a time-dependent voltage, a time-dependent current,    or a time-dependent charge.-   B10. The method of embodiment B8, wherein the distance between the    parallel plates is between 500 Angstroms and 1 micron.-   B11. The method of embodiment B1-B10, wherein the one or more    optical elements are disposed on a single chip that forms a    micro-electromechanical (MEMS) device.-   B12. The method of embodiment B11, wherein: a width of the chip is    less than or equal to 10 millimeters (mm); a length of the chip is    less than or equal to 10 mm; and a height of the chip is less than    or equal to 5 mm.-   B13. The method of embodiment B11, wherein: the one or more optical    elements comprise a Fabry-Perot interferometer including a first    plate and a second plate; one or more conductive elements are    coupled to each of the first plate and the second plate; and the one    or more conductive elements are configured to at least one of:    provide a trigger signal to the capacitance detector and the    photo-detector to cause the capacitance detector and the    photo-detector to measure an instantaneous mutual capacitance across    the first plate and the second plate; provide the varying input    signal to at least one of the first plate or the second plate to    cause a modulation of the first plate, the second plate, or the    first plate and the second plate; and provide data to the    capacitance detector representing the instantaneous mutual    capacitance, wherein the plurality of capacity values are generated    based on the data.-   B14. The method of embodiment B13, wherein the one or more    conductive elements are located exterior to the first plate and the    second plate such that, during application of the varying input    signal, a force causes the gap separating the first plate and the    second plate to vary.-   B15. The method of any one of embodiments B1-B14, further    comprising: generating a trigger signal operable to simultaneously    trigger (i) the photo-detector to detect the intensity of the light    output from the one or more optical elements and (ii) the    capacitance detector to detect the capacitance of the one or more    optical elements; and sending the trigger signal to the    photo-detector and the capacitance detector at a frequency of 10,000    Hz or greater.-   B16. The method of any one of embodiments B1-B15, wherein the one or    more optical elements comprise: a first plate and a second plate    disposed parallel to the first plate such that a gap between the    first plate and the second plate is formed; a liquid crystal    material is deposited in the gap between the first plate and the    second plate; the optical characteristic comprises a dielectric    constant of the liquid crystal material; and a value of the    dielectric constant is proportional to a value of the varying input    signal.-   B17. The method of embodiment B16, further comprising: generating a    plurality of dielectric values respectively based on the plurality    of capacitance values, wherein the plurality of transformation    values comprise a plurality of dielectric values of the liquid    crystal material.-   B18. The method of any one of embodiments B1-B17, wherein the one or    more optical elements are integrated into an image capture device    for determining the spectrum of the incoming light incident on the    pixel array, on a pixel-by-pixel basis.-   C1. A non-transitory computer-readable medium storing computer    program instructions that, when executed by one or more processors,    effectuate the method of any one of embodiments B1-B18.-   D1. A system for operating on incoming light, the system comprising:    one or more optical elements that, upon application of a varying    input signal thereto, cause a change to an optical characteristic of    the one or more optical elements, thereby resulting in a changing    interference pattern produced by the incoming light incident on the    one or more optical elements; a photo-detector configured to detect,    based on a trigger signal having a first frequency, an intensity of    light output from the one or more optical elements during    application of the varying input signal; and a capacitance detector    configured to detect, based on the trigger signal, a capacitance    associated with the optical characteristic during the application of    the varying input signal.-   D2. The system of embodiment D1, wherein the one or more optical    elements comprise: a first plate and a second plate disposed    parallel to the first plate such that a gap between the first plate    and the second plate is formed, wherein the optical characteristic    comprises a size of the gap which changes as a result of the    application of the varying input signal.-   D3. The system of embodiment D2, further comprising: one or more    processors configured to: obtain, from the capacitance detector, a    plurality of capacitance values representing the capacitance of the    one or more optical elements, obtain, from the photo-detector, a    plurality of signal values representing the intensity of the light    output from the one or more optical elements, and generate a    plurality of transformation values respectively based on the    plurality of capacitance values.-   D4. The system of embodiment D3, wherein the one or more processors    are further configured to: allow selection of a wavelength of the    incoming light for detection; and determine a presence of the    wavelength of the incoming light using some of the plurality of    transformation values and some of the plurality of signal values.-   D5. The system of embodiment D3, wherein the one or more processors    are further configured to: allow selection of a plurality of    wavelengths of the incoming light for detection; and determine a    presence of the plurality of wavelengths of the incoming light at    the plurality of wavelengths using some of the plurality of    transformation values and some of the plurality of signal values.-   D6. The system of embodiment D2, wherein: a metallic film or    dielectric material is disposed on an inner surface of each of the    first plate and the second plate; and each of the first plate and    the second plate are formed of glass.-   D7. The system of embodiment D2, wherein: the first plate is a first    conductive plate formed of a conductive transparent material; the    second plate is a second conductive plate formed of the conductive    transparent material; and multi-layer thin films forming a    reflective surface are disposed on an inner surface of each of the    first conductive plate and the second conductive plate.-   D8. The system of embodiment D2, wherein: the first plate is affixed    to a substrate and the second plate is suspended above the first    plate at a first distance; the varying input signal comprises a    first electrical signal applied to the one or more optical elements    during a first phase and a second electrical signal applied to the    one or more optical elements during a second phase; during the first    phase, application of the first electrical signal causes the second    plate to deform thereby decreasing a distance between the first    plate and the second plate from the first distance to a second    distance; and during second phase, application of the second    electrical signal causes the second plate to return to a starting    position prior to the first electrical signal being applied such    that the distance between the first plate and the second plate is    the first distance.-   D9. The system of any one of embodiments D1-D8, wherein the one or    more optical elements comprise parallel plates, the system further    comprising: a driving circuit configured to: generate the varying    input signal; and provide the varying input signal to the one or    more optical elements to cause the change to the optical    characteristic of the one or more optical elements, wherein the    optical characteristic comprises a distance between the parallel    plates.-   D10. The system of embodiment D9, wherein the varying input signal    comprises one of a time-dependent voltage, a time-dependent current,    or a time-dependent charge.-   D11. The system of embodiment D9, wherein the distance between the    parallel plates is between 500 Angstroms and 1 micron.-   D12. The system of embodiment D11-D11, wherein the one or more    optical elements are disposed on a single chip that forms a    micro-electromechanical (MEMS) device.-   D13. The system of embodiment D12, wherein: a width of the chip is    less than or equal to 10 millimeters (mm); a length of the chip is    less than or equal to 10 mm; and a height of the chip is less than    or equal to 5 mm.-   D14. The system of embodiment D12, wherein: the one or more optical    elements comprise a Fabry-Perot interferometer including a first    plate and a second plate; one or more conductive elements are    coupled to each of the first plate and the second plate; and the one    or more conductive elements are configured to at least one of:    provide a trigger signal to the capacitance detector and the    photo-detector to cause the capacitance detector and the    photo-detector to measure an instantaneous mutual capacitance across    the first plate and the second plate; provide the varying input    signal to at least one of the first plate or the second plate to    cause a modulation of the first plate, the second plate, or the    first plate and the second plate; and provide data to the    capacitance detector representing the instantaneous mutual    capacitance, wherein the plurality of capacity values are generated    based on the data.-   D15. The system of embodiment D14, wherein the one or more    conductive elements are located exterior to the first plate and the    second plate such that, during application of the varying input    signal, a force causes the gap separating the first plate and the    second plate to vary.-   D16. The system of any one of embodiments D3-D15, wherein the one or    more processors are further configured to: generate a trigger signal    operable to simultaneously trigger (i) the photo-detector to detect    the intensity of the light output from the one or more optical    elements and (ii) the capacitance detector to detect the capacitance    of the one or more optical elements; and send the trigger signal to    the photo-detector and the capacitance detector at a frequency of    10,000 Hz or greater.-   D17. The system of any one of embodiments D1-D16, wherein the one or    more optical elements comprise: a first plate and a second plate    disposed parallel to the first plate such that a gap between the    first plate and the second plate is formed; a liquid crystal    material is deposited in the gap between the first plate and the    second plate; the optical characteristic comprises a dielectric    constant of the liquid crystal material; and a value of the    dielectric constant is proportional to a value of the varying input    signal.-   D18. The system of embodiment D17, further comprising: one or more    processors configured to: obtain, from the capacitance detector, a    plurality of capacitance values representing the capacitance of the    one or more optical elements, obtain, from the photo-detector, a    plurality of signal values representing the intensity of the light    output from the one or more optical elements, generate a plurality    of transformation values respectively based on the plurality of    capacitance values; generate a plurality of dielectric values    respectively based on a plurality of capacitance values, wherein the    plurality of transformation values comprise a plurality of    dielectric values of the liquid crystal material.-   D19. The system of any one of embodiments D1-D18, wherein the one or    more optical elements are integrated into an image capture device    for determining the spectrum of the incoming light incident on the    pixel array, on a pixel-by-pixel basis.-   D20. The system of any one of embodiments D1-D19, wherein the one or    more optical elements are integrated into an image capture device,    such as a camera, for determining the spectrum of the incoming light    incident on the pixel array, on a pixel-by-pixel basis.-   D21. The system of any one of embodiments D1-D19, further    comprising: a current detector configured to measure a current drawn    by the one or more optical elements during the application of the    varying input signal, wherein the current is used to determine the    capacitance of the one or more optical elements.-   E1. A system for operating on incoming light, the system comprising:    one or more optical elements that, upon application of a varying    input signal thereto, cause a change to an optical characteristic of    the one or more optical elements, thereby resulting in a changing    interference pattern produced by the incoming light incident on the    one or more optical elements; a photo-detector configured to detect,    based on a trigger signal having a first frequency, an intensity of    light output from the one or more optical elements during    application of the varying input signal; and a current detector    configured to detect, based on the trigger signal, a current drawn    by the one or more optical elements during the application of the    varying input signal.-   E2. The system of embodiment A1, wherein the one or more optical    elements comprise: a first plate and a second plate disposed    parallel to the first plate such that a gap between the first plate    and the second plate is formed, wherein the optical characteristic    comprises a size of the gap which changes as a result of the    application of the varying input signal.-   E3. The system of embodiment E2, wherein the one or more processors    are further configured to: allow selection of a wavelength of the    incoming light for detection; and determine a presence of the    wavelength of the incoming light using some of the plurality of    transformation values and some of the plurality of signal values.-   E4. The system of embodiment E2, wherein the one or more processors    are further configured to: allow selection of a plurality of    wavelengths of the incoming light for detection; and determine a    presence of the plurality of wavelengths of the incoming light at    the plurality of wavelengths using some of the plurality of    transformation values and some of the plurality of signal values.-   E5. The system of embodiment E2, wherein: a metallic film or    dielectric material is disposed on an inner surface of each of the    first plate and the second plate; and each of the first plate and    the second plate are formed of glass.-   E6. The system of embodiment E2, wherein: the first plate is a first    conductive plate formed of a conductive transparent material; the    second plate is a second conductive plate formed of the conductive    transparent material; and multi-layer thin films forming a    reflective surface are disposed on an inner surface of each of the    first conductive plate and the second conductive plate.-   E7. The system of embodiment E2, wherein: the first plate is affixed    to a substrate and the second plate is suspended above the first    plate at a first distance; the varying input signal comprises a    first electrical signal applied to the one or more optical elements    during a first phase and a second electrical signal applied to the    one or more optical elements during a second phase; during the first    phase, application of the first electrical signal causes the second    plate to deform thereby decreasing a distance between the first    plate and the second plate from the first distance to a second    distance; and during second phase, application of the second    electrical signal causes the second plate to return to a starting    position prior to the first electrical signal being applied such    that the distance between the first plate and the second plate is    the first distance.-   E8. The system of any one of embodiments E1-E7, wherein the one or    more optical elements comprise parallel plates, the system further    comprising: a driving circuit configured to: generate the varying    input signal; and provide the varying input signal to the one or    more optical elements to cause the change to the optical    characteristic of the one or more optical elements, wherein the    optical characteristic comprises a distance between the parallel    plates.-   E9. The system of embodiment E8, wherein the varying input signal    comprises one of a time-dependent voltage, a time-dependent current,    or a time-dependent charge.-   E10. The system of embodiment E8, wherein the distance between the    parallel plates is between 500 Angstroms and 1 micron.-   E11. The system of embodiment E11-E10, wherein the one or more    optical elements are disposed on a single chip that forms a    micro-electromechanical (MEMS) device.-   E12. The system of embodiment E11, wherein: a width of the chip is    less than or equal to 10 millimeters (mm); a length of the chip is    less than or equal to 10 mm; and a height of the chip is less than    or equal to 5 mm.-   E13. The system of embodiment E11, wherein: the one or more optical    elements comprise a Fabry-Perot interferometer including a first    plate and a second plate; one or more conductive elements are    coupled to each of the first plate and the second plate; and the one    or more conductive elements are configured to at least one of:    provide a trigger signal to the current detector and the    photo-detector to cause the current detector and the photo-detector    to measure current drawn by the optical element; provide the varying    input signal to at least one of the first plate or the second plate    to cause a modulation of the first plate, the second plate, or the    first plate and the second plate; and provide data to the current    detector.-   E14. The system of embodiment E13, wherein the one or more    conductive elements are located exterior to the first plate and the    second plate such that, during application of the varying input    signal, a force causes the gap separating the first plate and the    second plate to vary.-   E15. The system of any one of embodiments E1-E14, wherein the one or    more processors are further configured to: generate a trigger signal    operable to simultaneously trigger (i) the photo-detector to detect    the intensity of the light output from the one or more optical    elements and (ii) the current detector to detect the current drawn    by the one or more optical elements; and send the trigger signal to    the photo-detector and the current detector at a frequency of 10,000    Hz or greater.-   E16. The system of any one of embodiments E1-E15, wherein the one or    more optical elements comprise: a first plate and a second plate    disposed parallel to the first plate such that a gap between the    first plate and the second plate is formed; a liquid crystal    material is deposited in the gap between the first plate and the    second plate; the optical characteristic comprises a dielectric    constant of the liquid crystal material; and a value of the    dielectric constant is proportional to a value of the varying input    signal.-   E16. The system of any one of embodiments E1-15, wherein the one or    more optical elements comprise: a first plate and a second plate    disposed parallel to the first plate such that a gap between the    first plate and the second plate is formed; a liquid crystal    material is deposited in the gap between the first plate and the    second plate; the optical characteristic comprises a dielectric    constant of the liquid crystal material; and a value of the    dielectric constant is proportional to a value of the varying input    signal.-   E17. The system of embodiment E16, further comprising: one or more    processors configured to: obtain, from the current detector, a    plurality of current values indicating a current drawn by the one or    more optical elements; generate a plurality of values based on the    plurality of current values, the plurality of capacitance values    representing the capacitance of the one or more optical elements;    and generate a plurality of dielectric values respectively based on    the plurality of capacitance values.-   E18. The system of any one of embodiments E1-E17, wherein the one or    more optical elements comprise: a first plate and a second plate    separated by a gap, wherein the optical characteristic of the one or    more optical elements comprises a size of the gap; and one or more    conductive elements configured to cause, based on the varying input    signal, the size of the gap separating the first plate and the    second plate to vary.-   E19. The system of embodiment E18, wherein the one or more    conductive elements are located exterior to the first plate and the    second plate such that, during application of the varying input    signal, a force causes the gap separating the first plate and the    second plate to vary.-   E20. The system of any one of embodiments E1-E19, wherein the one or    more optical elements are integrated into an image capture device,    such as a camera, for determining the spectrum of the incoming light    incident on the pixel array, on a pixel-by-pixel basis.

What is claimed is:
 1. A system for operating on incoming light,comprising: one or more optical elements that, upon application of avarying input signal, cause a change to an optical characteristic of theone or more optical elements, thereby resulting in a changinginterference pattern produced by the incoming light incident on the oneor more optical elements, the one or more optical elements including afirst plate and a second plate disposed parallel to the first plate suchthat a gap between the first plate and the second plate is formed,wherein each of the first plate and the second plate are partiallytransmissive and partially reflective, and wherein the opticalcharacteristic comprises a distance of the gap between the first plateand the second plate that changes as a result of the application of thevarying input signal across a first conductive electrode associated withthe first plate and a second conductive electrode associated with thesecond plate; a photo-detector configured to detect an intensity oflight output from the one or more optical elements during application ofthe varying input signal; a detector configured to detect one or more ofa capacitance, voltage, or current associated with the opticalcharacteristic relative to the application of the varying input signal;and one or more processors configured to: obtain, from the detector, aplurality of values each representing the optical characteristic at adifferent time during application of the varying input signal, obtain,from the photo-detector, a plurality of signal values each representingthe intensity of the light output from the one or more optical elementsat a different time during application of the varying input signal, andgenerate a plurality of transformation values respectively based on atleast some of the plurality of values.
 2. The system of claim 1, whereinthe one or more processors are further configured to: allow selection ofa wavelength of the incoming light or a certain spectrum of thewavelengths of the incoming light for detection; and determine apresence of the wavelength or the certain spectrum of the incoming lightusing some of the plurality of transformation values and some of theplurality of signal values.
 3. The system of claim 1, wherein the one ormore processors are further configured to: allow selection of aplurality of wavelengths of the incoming light for detection; anddetermine a presence of the plurality of wavelengths of the incominglight at the plurality of wavelengths using some of the plurality oftransformation values and some of the plurality of signal values.
 4. Thesystem of claim 1, wherein: each of the first plate and the second plateinclude: glass; and a conducting film or dielectric film disposed on aninner surface of each of the glass, thereby providing for the partiallytransmissive and the partially reflective aspects of each of the firstplate and the second plate.
 5. The system of claim 4 wherein theconducting film that forms each of the first conductive electrode andthe second conductive electrode is disposed on the inner surface of eachof the glass, and thus each conducting film also functions as one of afirst capacitive electrode and a second capacitive electrode to assistin detecting the plurality of values.
 6. The system of claim 5, wherein:the first plate is affixed to a substrate and the second plate isdisposed above the first plate at a first distance; the varying inputsignal comprises a first electrical voltage signal applied to the firstconductive electrode and the second conductive electrode, whereinapplication of the first electrical signal causes the second plate todeform from a starting position, thereby decreasing a distance betweenthe first plate and the second plate from the first distance to a seconddistance; wherein the plurality of signal values are obtained as one ormore of the capacitance, voltage, or current from the first capacitiveelectrode and the second capacitive electrode, and wherein conductingfilm on each of the first plate and second plate function as a combinedfirst electrode that includes both the first conductive electrode andthe first capacitive electrode and as a combined second electrode thatincludes the second conductive electrode and the second capacitiveelectrode.
 7. The system of claim 6, wherein the gap between the firstand second parallel plates is between 500 Angstroms and 1 micron.
 8. Thesystem of claim 5, wherein the one or more optical elements are disposedon a single chip that forms a micro-electromechanical (MEMS) device. 9.The system of claim 5, wherein: the conducting film on each of the firstplate and second plate function as a combined first electrode thatincludes the first conductive electrode and the first capacitiveelectrode and as a combined second electrode that includes the secondconductive electrode and the second capacitive electrode: receive thevarying input signal as a voltage to cause a deflection of the firstplate, the second plate, or the first plate and the second plate; andfunction as a parallel plate capacitor that provides an instantaneousmutual capacitance that is measured by the detector.
 10. The system ofclaim 9, wherein the one or more processors are further configured to:generate a trigger signal operable to simultaneously trigger (i) thephoto-detector to detect the intensity of the light output from the oneor more optical elements and (ii) the detector to detect the valueassociated with the optical characteristic; and send the trigger signalto the photo-detector and the detector.
 11. The system of claim 10wherein the trigger signal is provided at a predetermined frequencywhile the time varying signal is being applied.
 12. The system of claim4 wherein the first conductive electrode and the second conductiveelectrode are disposed on a surface of each of the glass associated withthe first plate and the second plate, respectively.
 13. The system ofclaim 12 wherein the first conductive electrode and the secondconductive electrode have one of a ring shape and a circular shape, andwherein the first capacitive electrode and the second capacitiveelectrode have the other of the ring shape and the circular shape, andwherein the second conductive electrode is electrically isolated fromthe second capacitive electrode.
 14. The system of claim 4, wherein: thefirst plate is affixed to a substrate and the second plate is disposedabove the first plate at a first distance; the varying input signalcomprises a first electrical signal applied to the first conductiveelectrode and the second conductive electrode, wherein application ofthe first electrical signal causes the second plate to deform from astarting position, thereby decreasing a distance between the first plateand the second plate from the first distance to a second distance. 15.The system of claim 4, wherein the one or more optical elements aredisposed on a single chip that forms a micro-electromechanical (MEMS)device.
 16. The system of claim 4, wherein: the first conductiveelectrode and the second conductive electrode are configured to at leastone of: receive the varying input signal to cause a deflection of thefirst plate, the second plate, or the first plate and the second plate;and function as a parallel plate capacitor that provides aninstantaneous mutual capacitance that is measured by the detector. 17.The system of claim 1, wherein: each of the first plate and the secondplate include: glass; and at least one conducting film and at least onedielectric film disposed as a multi-layer film on an inner surface ofeach of the glass, thereby providing for the partially transmissive andthe partially reflective aspects of each of the first plate and thesecond plate.
 18. The system of claim 1, wherein: the first plate isformed of a conductive transparent material that also functions as thefirst conductive electrode and a first multi-layer thin film forming areflective surface disposed on a first plate inner surface; the secondplate is formed of the conductive transparent material that alsofunctions as the second conductive electrode and a second multi-layerthin film forming another reflective surface disposed on a second plateinner surface.
 19. The system of claim 18, wherein the one or moreoptical elements are disposed on a single chip that forms amicro-electromechanical (MEMS) device.
 20. The system of claim 18,wherein: the first conductive electrode and the second conductiveelectrode are configured to at least one of: receive the varying inputsignal to cause a deflection of the first plate, the second plate, orthe first plate and the second plate; and function as a parallel platecapacitor that provides an instantaneous mutual capacitance that ismeasured by the detector.
 21. The system of claim 1, wherein: the firstplate is affixed to a substrate and the second plate is disposed abovethe first plate at a first distance; the varying input signal comprisesa first electrical signal applied to the first conductive electrode andthe second conductive electrode, wherein application of the firstelectrical signal causes the second plate to deform from a startingposition, thereby decreasing a distance between the first plate and thesecond plate from the first distance to a second distance.
 22. Thesystem of claim 21, wherein: a width of the chip is less than or equalto 10 millimeters (mm); a length of the chip is less than or equal to 10mm; and a height of the chip is less than or equal to 5 mm.
 23. Thesystem of claim 1, wherein the system further comprises: a drivingcircuit configured to: generate the varying input signal; and providethe varying input signal to the first conductive electrode and thesecond conductive electrode to cause the change to the distance betweenthe first parallel plate and the second parallel plate.
 24. The systemof claim 23, wherein the varying input signal comprises one of atime-dependent voltage, a time-dependent current, or a time-dependentcharge.
 25. The system of claim 23, wherein the gap between the firstand second parallel plates is between 500 Angstroms and 1 micron. 26.The system of claim 25, wherein the one or more optical elements aredisposed on a single chip that forms a micro-electromechanical (MEMS)device.
 27. The system of claim 1, wherein the one or more opticalelements are disposed on a single chip that forms amicro-electromechanical (MEMS) device.
 28. The system of claim 1,wherein: the first conductive electrode and the second conductiveelectrode are configured to at least one of: receive the varying inputsignal to cause a deflection of the first plate, the second plate, orthe first plate and the second plate; and function as a parallel platecapacitor that provides an instantaneous mutual capacitance that ismeasured by the detector.
 29. The system of claim 28, wherein the one ormore conductive elements are located on an outer side of the first plateand the second plate such that, application of the varying input signalresults in a force that causes the distance of the gap separating thefirst plate and the second plate to vary.
 30. The system of claim 28,wherein the one or more processors are further configured to: generate atrigger signal operable to simultaneously trigger (i) the photo-detectorto detect the intensity of the light output from the one or more opticalelements and (ii) the detector to detect the value associated with theoptical characteristic; and send the trigger signal to thephoto-detector and the detector.
 31. The system of claim 30 wherein thetrigger signal is provided at a predetermined frequency while the timevarying signal is being applied.
 32. The system of claim 1, wherein theone or more processors are further configured to: generate a triggersignal operable to simultaneously trigger (i) the photo-detector todetect the intensity of the light output from the one or more opticalelements and (ii) the detector to detect the value associated with theoptical characteristic; and send the trigger signal to thephoto-detector and the detector.
 33. The system of claim 32 wherein thetrigger signal is provided at a predetermined frequency while the timevarying signal is being applied.
 34. The system of claim 1 wherein theone or more optical elements are integrated into an image capture devicefor determining the spectrum of the incoming light incident on the pixelarray, on a pixel-by-pixel basis.
 35. A system for operating on incominglight, comprising: one or more optical elements that, upon applicationof a varying input signal thereto, cause a change to an opticalcharacteristic of the one or more optical elements, thereby resulting ina changing interference pattern produced by the incoming light incidenton the one or more optical elements, the one or more optical elementsincluding a first plate and a second plate disposed parallel to thefirst plate such that a gap between the first plate and the second plateis formed, wherein each of the first plate the second plate arepartially transmissive and partially reflective, wherein the opticalcharacteristic comprises a material having an index of refraction anddielectric constant that can vary that is deposited in the gap betweenthe first plate and the second plate, wherein the optical characteristiccomprises an index of refraction of the material, and wherein a value ofthe index of refraction is a function of the varying input signal; aphoto-detector configured to detect an intensity of light output fromthe one or more optical elements during application of the varying inputsignal; a detector configured to detect one or more of a capacitance,voltage or current associated with the optical characteristic relativeto the application of the varying input signal; and one or moreprocessors configured to: obtain, from the detector, a plurality ofvalues each representing the optical characteristic, obtain, from thephoto-detector, a plurality of signal values representing the intensityof the light output from the one or more optical elements, and generatea plurality of transformation values respectively based on at least someof the plurality of values.
 36. The system of claim 35, wherein the oneor more processors are further configured to: allow selection of awavelength of the incoming light or a certain spectrum of thewavelengths of the incoming light for detection; and determine apresence of the wavelength or the certain spectrum of the incoming lightusing some of the plurality of transformation values and some of theplurality of signal values.
 37. The system of claim 35, wherein the oneor more processors are further configured to: allow selection of aplurality of wavelengths of the incoming light for detection; anddetermine a presence of the plurality of wavelengths of the incominglight at the plurality of wavelengths using some of the plurality oftransformation values and some of the plurality of signal values. 38.The system of claim 35, wherein: each of the first plate and the secondplate include: glass; and a conducting film or dielectric film disposedon an inner surface of each of the glass, thereby providing for thepartially transmissive and the partially reflective aspects of each ofthe first plate and the second plate.
 39. The system of claim 35,wherein: each of the first plate and the second plate include: glass;and at least one conducting film and at least one dielectric filmdisposed on an inner surface of each of the glass, thereby providing forthe partially transmissive and the partially reflective aspects of eachof the first plate and the second plate.
 40. The system of claim 35,wherein the one or more processors are further configured to: generate aplurality of index of refraction values respectively based on theplurality of values, wherein the plurality of transformation valuescomprise a plurality of index of refraction values of the liquid crystalmaterial.
 41. The system of claim 35, wherein the one or more opticalelements are integrated into an image capture device for determining thespectrum of the incoming light incident on the pixel array, on apixel-by-pixel basis.
 42. A method for operating on incoming light, themethod being implemented by one or more processors executing computerprogram instructions, the method comprising: obtaining, from a detectorconfigured to detect one or more of a capacitance, voltage or currentassociated with an optical characteristic that comprises a distancebetween two parallel plates that changes upon application of a varyinginput signal, the two parallel plates being partially transmissive andpartially reflective, wherein a plurality of values representing theoptical characteristic are obtained from the detection of the one ormore of the capacitance, voltage or current, and wherein uponapplication of the varying input signal, the two parallel plates cause achange to the optical characteristic thereby resulting in a changinginterference pattern produced by incoming light incident on the twoparallel plates; obtaining, from a photo-detector configured to detectan intensity of light output from the two parallel plates duringapplication of the varying input signal, a plurality of signal valuesrepresenting the intensity of the light output from the two parallelplates, generating a plurality of transformation values respectivelybased on at least some of the plurality of values; and using at leastsome of the plurality of transformation values and at least some of theplurality of signal values to determine a spectrum of the incominglight.
 43. The method of claim 42, further including the steps of theone or more processors generating a trigger signal operable tosimultaneously trigger (i) the photo-detector to detect the intensity ofthe light output from the one or more optical elements and (ii) thedetector to detect the value associated with the optical characteristic;and sending the trigger signal to the photo-detector and the detector.44. The method of claim 43, further including the step of the one ormore processors allowing for selection of a wavelength of the incominglight or a certain spectrum of the wavelengths of the incoming light fordetection; and determining a presence of the wavelength or the certainspectrum of the incoming light using some of the plurality oftransformation values and some of the plurality of signal values. 45.The method of claim 43, further including the step of the one or moreprocessors allowing for selection of a plurality of wavelengths of theincoming light for detection; and determining a presence of theplurality of wavelengths of the incoming light at the plurality ofwavelengths using some of the plurality of transformation values andsome of the plurality of signal values.
 46. The method according toclaim 43 wherein the step of obtaining a plurality of values includesthe step of using a capacitance detector that detects the capacitancebetween two capacitance electrodes that are each associated with one ofthe two parallel plates.
 47. The method according to claim 46 whereinthe step of obtaining a plurality of values further includes the step ofusing a current detector that detects the current between electrodesthat are each associated with one of the two parallel plates.
 48. Thesystem of claim 43 wherein the one or more optical elements areintegrated into an image capture device for determining the spectrum ofthe incoming light incident on the pixel array, on a pixel-by-pixelbasis.
 49. A system for operating on incoming light based on a varyinginput signal and a trigger signal being provided thereto, the systemcomprising: two parallel plates that are partially transmissive andpartially reflective that, upon application of the varying input signal,cause a change to an optical characteristic of the two parallel plates,thereby resulting in a changing interference pattern produced by theincoming light incident on the two parallel plates; a photo-detectorconfigured to detect, based on the trigger signal having a firstfrequency, an intensity of light output from the two parallel platesduring application of the varying input signal; and a detectorconfigured to detect, based on the trigger signal, one or more of acapacitance, voltage or current associated with the opticalcharacteristic during the application of the varying input signal. 50.The system of claim 49, wherein: each of the two parallel platesinclude: glass; and at least one conducting film and at least onedielectric film disposed as a multi-layer film on an inner surface ofeach of the glass, thereby providing for the partially transmissive andthe partially reflective aspects of each of the two parallel plates. 51.The system of claim 50, wherein the one or more optical elements aredisposed on a single chip that forms a micro-electromechanical (MEMS)device.
 52. The system of claim 49, wherein: each of the two parallelplates include: glass; and a conducting film or dielectric film disposedon an inner surface of each of the glass, thereby providing for thepartially transmissive and the partially reflective aspects of each ofthe two parallel plates.
 53. The system of claim 52 wherein a conductingfilm on each of the first plate and second plate functions as a combinedfirst electrode that includes a first conductive electrode and a firstcapacitive electrode and as a combined second electrode that includes asecond conductive electrode and a second capacitive electrode, andwherein receiving the varying input signal as a voltage across the firstand second combined electrodes causes a deflection of the first plate,the second plate, or the first plate and the second plate; and the firstand second combined electrodes also function as a parallel platecapacitor that provides an instantaneous mutual capacitance that ismeasured by the detector.
 54. The system of claim 52 wherein a firstconductive electrode and a second conductive electrode are disposed on asurface associated with the first plate and the second plate,respectively.
 55. The system of claim 54 wherein the first conductiveelectrode and the second conductive electrode have one of a ring shapeand a circular shape, and wherein the first capacitive electrode and thesecond capacitive electrode have the other of the ring shape and thecircular shape, and wherein the second conductive electrode iselectrically isolated from the second capacitive electrode.
 56. Thesystem of claim 55, wherein the one or more optical elements aredisposed on a single chip that forms a micro-electromechanical (MEMS)device.
 57. The system of claim 52, wherein the one or more opticalelements are disposed on a single chip that forms amicro-electromechanical (MEMS) device.
 58. The system of claim 49,wherein: the first plate is formed of a conductive transparent materialthat also functions as the first conductive electrode and a firstmulti-layer thin film forming a reflective surface disposed on a firstplate inner surface; the second plate is formed of the conductivetransparent material that also functions as the second conductiveelectrode and a second multi-layer thin film forming another reflectivesurface disposed on a second plate inner surface.
 59. The system ofclaim 58, wherein the one or more optical elements are disposed on asingle chip that forms a micro-electromechanical (MEMS) device.
 60. Thesystem according to claim 58 wherein the detector includes a capacitancedetector.
 61. The detector according to claim 60 wherein the detectorfurther includes a current detector.
 62. The system according to claim58 wherein the varying input signal creates electrostatic forces thatcause the optical characteristic to change.